Author: admin

  • Can I get a quote for an auto electrical problem?

    Quick answer

    Yes. For a known job, like a battery, a globe or an accessory install, most auto electricians can give a firm price over the phone or online if you supply your vehicle details. For a fault, such as a no-start, a warning light or a battery that keeps going flat, you’ll usually get a price for diagnosis first, then a firm quote for the repair once the cause is found. The more detail and photos you give, the more accurate the quote.

    Is this a DIY job?

    • Difficulty: Easy
    • Time: 10 to 15 minutes to gather the details
    • Tools: phone camera, notepad, your registration papers or the car’s compliance plate
    • Skills: none

    Why faults often need diagnosis first

    The same symptom can have several causes. A car that won’t start could need a new terminal clamp, a battery, a starter motor or an immobiliser repair. A fair auto electrician won’t guess. Expect one of these:

    • Fixed-price job: the work and parts are known (battery fitted, trailer plug wired, reversing camera installed).
    • Diagnostic fee, then quote: a set fee or time to find the fault, then a written quote for the repair.
    • Estimate with a range: a likely cost with a clear limit, and a promise to call you before going over it.

    Step by step

    1. Write down your vehicle details. Make, model, year, engine and transmission. The VIN is on your registration papers and usually on a plate in the engine bay or at the base of the windscreen.
    2. Describe the problem in plain words. What happens, what doesn’t, and what you hear, see or smell.
    3. Say when it happens. Every time, or only sometimes? Cold or hot engine? After rain? Only when it’s been parked overnight? Intermittent faults take longer to find, so these details save time and money.
    4. Note any history. Recent battery change, jump start, accident, new accessories, or work done by someone else.
    5. Take photos. The dashboard with warning lights on (engine running if safe), any damaged or corroded parts, and any aftermarket wiring. A short video helps with noises.
    6. If you have codes, include them. If you’ve read fault codes with an OBD2 reader, send the exact codes. (see How do I read fault codes with an OBD2 scanner?)
    7. For installs, describe what you want. For example: dual battery with a DC-DC charger and where the second battery goes; brake controller with the trailer’s details; or reversing camera with or without a new screen.
    8. Ask the right questions. How is diagnosis charged? Is there a call-out fee? Does the price include GST? What warranty applies? Will they contact you before extra work?
    9. Get it in writing. A written quote protects both of you. It should list the work, parts, labour and how long the price is valid. An estimate is only a best guess, so ask to be called before the cost goes over an agreed limit.
    10. Compare like with like. Check each quote covers the same parts, scope and warranty.

    Specs table

    What to send with a quote request

    Item Example
    Vehicle 2016 Toyota Hilux 2.8 diesel, auto
    VIN From rego papers or compliance plate
    Problem Battery goes flat after 3 days parked
    When Started after a new stereo was fitted last month
    Warning lights None (photo attached)
    Codes None read
    Where the car is Suburb or postcode; can it be driven?
    What you want Find and fix the drain; quote before repair

    What you’ll need

    No parts to buy. If you’d like to read engine codes yourself before calling:

    • OBD2 code reader
    • digital multimeter (to note your battery voltage)

    When to call an auto electrician

    • Straight away if a red warning light is on, you smell burning, or the car is unsafe to drive. Don’t drive it to a workshop if the oil pressure, temperature or brake warning lights are on: ask about mobile service or towing. (see What should I do when a warning light or fault code comes up on my dashboard?)
    • When simple checks haven’t found the fault.
    • For any work involving airbags/SRS, hybrid or EV high-voltage systems, or air conditioning refrigerant.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

    Find an auto electrician near you

    Related questions

    Q: Why won’t an auto electrician give me a firm price over the phone? A: Because the same symptom can have several causes. A firm price before diagnosis would either be a guess or padded to cover the worst case. A diagnostic fee followed by a firm quote is usually fairer.

    Q: Is a diagnostic fee taken off the repair price? A: Some businesses deduct it if you go ahead with the repair, others don’t. Ask before you book.

    Q: How many quotes should I get? A: For a large install or an expensive repair, two or three written quotes are reasonable. For a diagnosis, it’s usually better to pick one business and let them find the fault.

    Q: How much do auto electricians charge? A: Rates vary by location and job. See the researched ranges in the cost guide. (see How much do auto electricians charge in Australia?)

    Sources

    1. NSW Government, “Consumer guarantees” – services must be provided with acceptable care and skill and deliver agreed results. https://www.nsw.gov.au/legal-and-justice/consumer-rights-and-protection/guarantees-contracts-and-warranties/consumer-guarantees (checked October 2026)
    2. NRMA, “What do my dashboard warning lights mean” – red warning lights need prompt action; have a technician diagnose faults. https://mynrma.com.au/cars-and-driving/car-servicing/resources/what-do-my-dashboard-warning-lights-mean (checked October 2026)
    3. NT Government, “Quotes and estimates” – a quote is a fixed price that becomes a contract once accepted; an estimate is not fixed; what a written quote should include; set a limit and ask to be contacted. https://nt.gov.au/law/rights/quotes-and-estimates (checked October 2026)

  • Have rats or mice chewed my car wiring?

    Quick answer

    Signs of rodent damage include sudden warning lights or odd electrical faults after the car has been parked, chewed insulation or loom tape, droppings, nesting material (leaves, paper, insulation) under the bonnet or in the air filter box, and a burning or unpleasant smell. Rodents shelter in warm engine bays and gnaw to wear down their teeth. Small, visible damage can sometimes be repaired, but damaged looms often need professional repair, and some insurance policies exclude rodent damage, so check your policy.

    Is this a DIY job?

    • Difficulty: Easy to inspect; Pro to repair most wiring damage
    • Time: 15 to 30 minutes to inspect
    • Tools: torch, gloves, mask, camera
    • Skills: careful looking

    Repairing wiring properly means matching wire sizes, staggering joints, sealing against moisture and protecting the loom again. Damaged looms may also carry sensors, airbag or driver-assistance circuits. Most owners leave repairs to an auto electrician.

    Step by step

    1. Don’t keep driving with new, unexplained warnings. If warning lights appear suddenly, the engine runs badly, or you smell burning, park safely and investigate before driving further.
    2. Open the bonnet and look carefully with a torch. Wear gloves and a mask: droppings and nests can carry disease.
    3. Look for the tell-tale signs: – chewed insulation, exposed copper or bitten loom tape and conduit – droppings, urine stains, food scraps, nests in corners, on top of the engine or in the air filter box – chewed insulation pads on the underside of the bonnet
    4. Check the air intake and cabin filter. Rodents often nest in air boxes and the cabin air intake below the windscreen. A blocked or chewed filter can cause smells and poor airflow.
    5. Photograph everything. Photos help with an insurance claim and a repair quote.
    6. Check your insurance policy. Some policies exclude damage by rodents or vermin. Ask your insurer before starting repairs.
    7. Get the wiring repaired. An auto electrician will trace every damaged wire, repair or replace the section, and re-protect the loom. Then any fault codes are read and cleared.
    8. Clean out nests safely. Wear gloves and a mask. Don’t sweep, vacuum or blow out dry droppings. Spray the nest and droppings with disinfectant or a diluted bleach solution, let it soak for a few minutes, then pick it up with paper towel and seal it in a bag. Wash your hands afterwards.
    9. Reduce the chance of a return visit. See the prevention list below.

    Specs table

    Prevention

    What to do Why
    Don’t leave food, pet food or rubbish in or near the car Food attracts rodents
    Keep the garage or parking area tidy and sealed Fewer hiding places and entry points
    Trim branches and vegetation near where the car parks Reduces access
    Use baits only in lockable bait stations, or traps Bait stations keep pets, children and other animals out; follow label directions
    Start and drive the car regularly A car that sits for weeks is more inviting
    Check under the bonnet if the car has been parked for a while Catch damage early
    Consider rodent-deterrent tape or mesh over air intakes Some owners use these; results vary

    Common symptoms after rodent damage

    Symptom Possible cause
    Sudden check engine or other warning lights Sensor wiring chewed
    Car won’t start or cranks but won’t start Starting, sensor or fuel pump circuit damaged
    Lights, wipers or gauges acting oddly Chewed body or lighting wiring
    Burning smell Short circuit, or nest on a hot exhaust
    Musty smell through the vents Nest or droppings in the cabin air intake

    What you’ll need

    For prevention and inspection:

    • rodent deterrent tape
    • split loom tube (to protect exposed wiring after repair)
    • cabin air filter (if contaminated)

    For repair (usually by a professional): automotive wire, solder sleeve connectors, adhesive heat shrink, loom tape.

    When to call an auto electrician

    • Any chewed wiring, especially in the engine loom, near sensors or near the airbag and driver-assistance wiring.
    • Warning lights or running problems after rodent activity.
    • Hybrid or EV high-voltage (orange) cables are damaged. Don’t touch them: professional-only.
    • There’s a burning smell, melted insulation or signs of a short circuit.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

    Find an auto electrician near you

    Related questions

    Q: Does car insurance cover rat damage? A: It depends on the policy. Some exclude damage by rodents or vermin. Check your product disclosure statement or ask your insurer before repairs start.

    Q: Why do rats chew car wiring? A: Rodents gnaw constantly to keep their teeth worn down, and warm, sheltered engine bays are attractive in cooler weather. Food and nesting material nearby make it more likely.

    Q: How much does it cost to repair rodent damage? A: It depends on how much wiring is damaged and whether a loom must be replaced. Minor repairs can be modest; extensive damage can cost thousands of dollars or even make a car uneconomical to repair. Get a written quote after inspection.

    Q: Do ultrasonic rodent repellers work in cars? A: Results are mixed and there’s limited independent evidence. Removing food, sealing access and regular use of the car are more reliable.

    Sources

    1. The New Daily, “Rats car damage” (April 2021) – rodents seeking warmth in engine bays, gnawing on wiring; example repair cost around $2,000 and a car written off; insurance exclusion example; Brisbane City Council prevention advice; bait stations. https://thenewdaily.com.au/news/queensland/2021/04/23/rats-car-damage (checked October 2026)
    2. Brisbane City Council, “Rats and mice” – baits and traps; follow label safety instructions; lockable bait stations and traps are safer around children and pets. https://www.brisbane.qld.gov.au/environment-waste/natural-environment/biodiversity-brisbane/wildlife-brisbane/pest-animals-invasive-species/rats-mice (checked October 2026)
    3. SA Health, “Rats and mice – prevention and control” – remove food and shelter, cut back vegetation, seal entry points; rodents can carry diseases such as leptospirosis. https://www.sahealth.sa.gov.au/wps/wcm/connect/Public+Content/SA+Health+Internet/Conditions/Bites+stings+and+pests/Rats+and+mice+prevention+and+control (checked October 2026)
    4. NSW Health, “Staying healthy during a mouse plague” – diseases spread by rodent urine and droppings; wear gloves, clean with disinfectant or bleach, wash hands. https://www.health.nsw.gov.au/environment/factsheets/Pages/mouse-plague.aspx (checked October 2026)
    5. US Centers for Disease Control and Prevention, “How to clean up after rodents” – soak droppings and nests with disinfectant before removal; don’t sweep or vacuum; bag and seal. https://cdc.gov/healthy-pets/rodent-control/clean-up.html (checked October 2026)

  • How do I replace an interior light globe?

    Quick answer

    Switch the interior light off, gently prise the clear lens off with a plastic trim tool, and pull the old globe out. Most interior lights use either a festoon globe (a small tube with a cap at each end) or a W5W (T10) wedge globe. Fit a new one of the same type and size, test it, and clip the lens back on.

    Is this a DIY job?

    • Difficulty: Easy
    • Time: 5 to 15 minutes
    • Tools: plastic trim tool (or a small flat screwdriver wrapped in tape), clean cloth
    • Skills: a gentle touch with plastic clips

    This is one of the easiest jobs on a car. The main risks are scratching or cracking the lens, and pulling on wiring in the roof lining.

    Step by step

    1. Switch the light off. Set the interior light switch to off (not “door”), so it doesn’t come on while you work. The globe can be hot if it’s been on.
    2. Find the notch. Most lenses have a small slot or notch on one edge for a trim tool. The owner’s manual usually shows where.
    3. Prise the lens off gently. Slide the trim tool into the notch and lever carefully. Work around the edge rather than forcing one point. Keep the lens: they crack easily.
    4. Identify the globe. – Festoon: a glass tube with a metal cap at each end, held between two spring clips. – Wedge (W5W / T10): a small glass globe with a flat plastic or glass base that pushes straight in. – Small bayonet (e.g. R5W/R10W): twists out like a brake light globe. – LED module: a circuit board with no separate globe. These usually aren’t serviceable.
    5. Remove the old globe. Festoon: lift one end out of its clip with a fingernail or trim tool, then the other. Wedge: pull straight out. Bayonet: push, twist anticlockwise, pull out.
    6. Match the size. Festoon globes come in several lengths. Measure the old one end to end in millimetres, or read the size printed on the cap, and buy the same length.
    7. Fit the new globe. Festoon: push it between the clips so it’s held firmly at both ends. If it’s loose, gently squeeze the clips closer together. Wedge: push it straight in.
    8. Test it. Switch the light on. If you’ve fitted an LED and it doesn’t light, take it out, turn it around (or rotate the wedge 180 degrees) and try again: many LEDs only work one way round.
    9. Refit the lens. Line up the tabs and press it home until it clicks.

    Specs table

    Common interior globe types (12V)

    Type Shape Typical wattage Base Typical use
    W5W (T10, US 168) Small wedge 5 W W2.1×9.5d Map lights, boot lights, number plates, side markers
    C5W Festoon 5 W Festoon caps (36 mm is common; other lengths exist) Dome lights, boot lights
    R5W Small bayonet 5 W BA15s Some older interior and number plate lamps

    Festoon globes come in several lengths. Always match the length of the old globe. Your owner’s manual lists the types for your car.

    What you’ll need

    • festoon globe (matching length) or W5W T10 wedge globe
    • plastic trim tool
    • Optional: LED festoon or LED T10 wedge (see related questions)

    When to call an auto electrician

    • The new globe doesn’t work and the fuse is fine. Check the door switches and wiring, or have it tested.
    • The interior light stays on with the doors shut, or comes on by itself. That can flatten the battery. (see Why does my car battery keep going flat?)
    • The light is in a roof console near the A-pillars or a sunroof and you’d need to remove the console. Curtain airbag wiring and modules can be nearby.
    • The light is an LED module with no separate globe.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

    Find an auto electrician near you

    Related questions

    Q: Can I put LED globes in my interior lights? A: In most cars, yes, and they run cooler and draw less power. If the light flickers or glows faintly when off, the car may be checking the circuit with a small current. A CAN-bus-rated LED may fix it.

    Q: Why won’t my LED interior globe work? A: Most LEDs only work one way round. Turn it around and try again.

    Q: Why does my interior light stay on? A: The light switch may be set to “on”, a door, boot or bonnet switch may be faulty, or a door may not be fully latched. Check each door switch.

    Q: How do I know which festoon size to buy? A: Measure the old globe from end to end, or check the size printed on its cap. Common lengths vary, so don’t guess.

    Sources

    1. Wikipedia, “List of automotive light bulb types” – W5W, C5W and R5W base types and wattages; W5W ANSI equivalent 168. https://en.wikipedia.org/wiki/List_of_automotive_light_bulb_types (checked October 2026)
    2. Narva, “12V 5W T-10 W5W wedge globe” product page – 12V 5W, W2.1 x 9.5d base, ECE R37 category W5W; used for park, interior, number plate and side marker lamps. https://www.narva.com.au/products/47501BL/12v-5w-w2-1-x-9-5d-w5w-wedge-globes–blister-pack-of-2- (checked October 2026)
    3. Narva, “12V 5W SV8-5.8 C5W festoon globes” product page – 12V 5W C5W festoon, 11 x 36 mm. https://www.narva.com.au/products/47254BL (checked October 2026)

  • How much solar do I need for my caravan?

    Quick answer

    Work out how much power you use in a day, then size your solar to replace it, with a margin for cloudy days and less-than-ideal panel angles. Panels rarely produce their full rated output: shading, heat, dust, panel angle, time of year and where you are in Australia all reduce it. A common planning approach is to estimate daily solar harvest as panel watts × an assumed number of peak sun hours × a system efficiency factor, then compare it with your daily use. Your battery size decides how long you can last when the sun doesn’t cooperate.

    Is this a DIY job?

    • Difficulty: Easy to calculate; Medium to install portable panels; Pro for roof-mounted panels, regulators and wiring into an existing system
    • Time: 30 minutes to work out
    • Tools: appliance labels or manuals, a battery monitor (if you have one), calculator
    • Skills: simple maths

    Step by step

    1. List your 12V appliances. Fridge, lights, water pump, fans, USB charging, diesel heater, TV, and anything run through an inverter.
    2. Find each one’s power draw. Look for amps (A) or watts (W) on the label or in the manual. For 12V, amps ≈ watts ÷ 12.
    3. Estimate hours of use per day. A fridge cycles on and off, so use the maker’s daily energy figure if it gives one, or measure it with a battery monitor.
    4. Work out daily use in amp-hours (Ah). For each appliance: amps × hours per day. Add them up.
    5. Add inverter losses. Anything run through an inverter uses more than its rated power from the battery. Allow extra, or check the inverter maker’s efficiency figure. (see How do I choose and install an inverter?)
    6. Estimate daily solar harvest. For planning: panel watts ÷ 12 × assumed peak sun hours × efficiency factor = Ah per day. The peak sun hours you can expect depend on location and season; use a conservative figure for winter or southern trips. An efficiency factor (for heat, dust, angle and cable and regulator losses) is often assumed to be around 0.7, but treat it as a rough guide.
    7. Compare and add a margin. Your solar harvest on a typical day should comfortably exceed your daily use if you want to stay put. Cloudy days can produce much less.
    8. Size the battery for the gap. Battery capacity covers nights and cloudy days. Lithium lets you use more of its rated capacity than AGM.
    9. Choose a suitable regulator. MPPT regulators generally get more from the panels than PWM regulators, especially in low light and on larger systems. PWM can suit a small system on a budget. Many DC-DC chargers include one. (see DC-DC charger or VSR isolator: which do I need?)
    10. Check with real numbers. Once set up, a battery monitor shows what you actually use and harvest. Adjust from there.

    Specs table

    Worked example (illustration only, not a recommendation)

    Item Draw Hours/day Ah/day
    12V compressor fridge (average) 2.5 A 24 (average, including cycling) 60
    LED lights 2 A 4 8
    Water pump 5 A 0.5 2.5
    USB devices 2 A 3 6
    Total about 77 Ah

    Solar estimate using the planning formula, assuming 5 peak sun hours and an efficiency factor of 0.7:

    Panel size Estimated Ah/day
    200 W 200 ÷ 12 × 5 × 0.7 ≈ 58 Ah
    300 W ≈ 88 Ah
    400 W ≈ 117 Ah

    In this example, 200 W wouldn’t keep up on a good day; 300 W would cover the daily use with a small margin; 400 W gives more room for cloud or extra loads. Fewer sun hours (for example in winter) reduce every figure. Your own appliance draws and conditions will differ.

    What you’ll need

    • solar panel 12V or portable folding solar panel
    • MPPT solar regulator (or a DC-DC charger with solar input)
    • Anderson plug 50A and solar extension lead
    • battery monitor
    • inline fuse holder / circuit breaker

    When to call an auto electrician

    • You’re installing roof panels and running cable into the van.
    • You’re adding solar to a system with a DC-DC charger, lithium battery or inverter.
    • The battery isn’t charging as expected from solar.
    • Any 240V work. Fixed 240V wiring in a caravan must be done by a licensed electrician.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

    Find an auto electrician near you

    Related questions

    Q: Portable or roof-mounted solar? A: Roof panels are always connected and need no setting up. Portable panels can be aimed at the sun and placed in sun while the van is in shade. Many people use both.

    Q: Why am I getting less solar than my panels are rated for? A: Panel ratings are measured in ideal lab conditions. Heat, angle, dust, shading, time of year and cable losses all reduce real output.

    Q: Do I need an MPPT regulator? A: It’s not essential, but MPPT generally harvests more energy than PWM. Many DC-DC chargers have MPPT built in.

    Q: How long will my battery last without sun? A: Divide the battery’s usable capacity by your daily use, after allowing for any partial solar. Lithium lets you use more of its rated capacity than AGM.

    Sources

    1. Signature Camper Trailers, “How much solar do you need?” – planning formula (panel watts ÷ 12 × 5 peak sun hours × 0.7 efficiency); daily use in Ah; cloudy-day reduction (manufacturer guide; assumptions not independently sourced). https://signaturecampertrailers.com.au/how-much-solar-do-you-need/ (checked October 2026)
    2. REDARC, “Regulating the sun” – MPPT regulators harvest more from the panels, especially in low light and on larger systems; PWM suits small, budget systems. https://www.redarcelectronics.com/au/discover/regulating-the-sun/ (checked October 2026)
    3. WorkSafe ACT, “Electrical incident” – 240V installations in caravans and transportable structures should be done by a licensed electrician and certified to AS/NZS 3001. https://www.worksafe.act.gov.au/health-and-safety-portal/safety-alerts/electrical-incident (checked October 2026)
    4. Consumer, Building and Occupational Services Tasmania, “Using electricity safely in caravans and tents” – don’t do DIY electrical work on a caravan; only a licensed electrician can. https://cbos.tas.gov.au/topics/technical-regulation/electrical-standard-safety/using-electricity-safely-in-caravans-and-tents (checked October 2026)

  • DC-DC charger or VSR isolator: which do I need?

    Quick answer

    A VSR (voltage sensitive relay, or isolator) simply connects your auxiliary battery to the vehicle’s charging system when the engine is running. A DC-DC charger converts the vehicle’s power into a proper multi-stage charge for the auxiliary battery. Choose a DC-DC charger if your vehicle has a smart (variable-voltage) alternator, your auxiliary battery is lithium, the cable run is long (canopy, tray or caravan), or you want solar charging built in. A VSR can still suit an older vehicle with matching lead-acid batteries close together under the bonnet.

    Is this a DIY job?

    • Difficulty: Medium for a VSR under the bonnet; Pro for a DC-DC charger with long cable runs, lithium or a smart alternator
    • Time: 2 to 6 hours
    • Tools: heavy cable crimper, cable cutter, multimeter, drill and grommets
    • Skills: high-current wiring and fusing

    Step by step: choosing

    Dual battery system overview The alternator charges the starting battery. A charging device, either a VSR or a DC-DC charger, links the starting battery to the auxiliary battery, with a fuse or circuit breaker near each battery. Solar can feed the auxiliary battery through a regulator or the DC-DC charger. Accessories such as the fridge and lights run from the auxiliary battery through a fuse block. How a dual battery system works Alternator engine running Starting battery starts the engine, runs the vehicle Charging device VSR (isolator) or DC-DC charger Auxiliary battery deep-cycle AGM or lithium securely mounted Fuse block one fuse per accessory Solar panel via regulator or the DC-DC solar input Fridge Lights, USB fuse fuse Key points Fuse or circuit breaker close to each battery. Engine off: batteries are separated, so accessories can’t flatten the starting battery. Smart alternator, lithium or long cable run: a DC-DC charger is usually the better choice.
    Dual battery system overview showing where the VSR or DC-DC charger sits
    1. Find out what alternator you have. Many newer vehicles (roughly 2015 on, and some older ones) have smart or variable-voltage alternators, often alongside stop-start or a battery sensor on the negative terminal. Check the owner’s manual or ask the vehicle maker. A smart alternator may drop its output once the starting battery is full, so a VSR may not see enough voltage to charge the auxiliary battery properly.
    2. Check your auxiliary battery type. Lithium (LiFePO4) batteries need a charge profile to suit them. A DC-DC charger with a lithium setting is the usual choice. A VSR generally suits matching lead-acid batteries.
    3. Measure the cable run. Long cables lose voltage. A DC-DC charger mounted near the auxiliary battery makes up for some of that loss. A VSR can’t, so the auxiliary battery may only partly charge. (see What size cable do I need for my 12V accessory?)
    4. Decide on solar. Many DC-DC chargers have a built-in solar input (often MPPT). With a VSR, you need a separate solar regulator.
    5. Consider cost and simplicity. A VSR is simpler and cheaper. A DC-DC charger costs more but usually charges more completely.
    6. Check the charger’s input rules. Some DC-DC chargers need an ignition or “D+” signal to work with smart alternators. Follow the maker’s instructions.
    7. Fuse both ends. Fit a fuse or circuit breaker near the starting battery and near the auxiliary battery (or at the charger output), sized for the cable.

    Specs table

    Situation Usually suits
    Older vehicle, conventional alternator, two lead-acid batteries side by side VSR
    Smart or variable-voltage alternator DC-DC charger
    Lithium auxiliary battery DC-DC charger with lithium profile
    Auxiliary battery in a canopy, tray or caravan (long run) DC-DC charger near the auxiliary battery
    Want solar charging through the same unit DC-DC charger with solar input
    Lowest cost, simplest install VSR (if the situation above suits)

    What you’ll need

    • DC-DC charger or voltage sensitive relay
    • heavy duty single core auto cable or twin core auto cable
    • circuit breaker / MIDI fuse holder (one each end)
    • cable lugs and adhesive heat shrink
    • Anderson plug 50A (for caravan or trailer connections)

    When to call an auto electrician

    • Your vehicle has a smart alternator, a battery sensor, stop-start or a battery management system.
    • You’re installing a lithium battery or running cable to a canopy, tray or caravan.
    • The auxiliary battery isn’t fully charging after a day’s driving.
    • You want a combined system with solar, an inverter and a battery monitor.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

    Find an auto electrician near you

    Related questions

    Q: Can I use a VSR with a lithium auxiliary battery? A: Generally not recommended. Lithium batteries need a suitable charge profile, and they can draw very high current from the alternator through a VSR. A DC-DC charger with a lithium setting is the usual approach.

    Q: How do I know if I have a smart alternator? A: Signs include stop-start, a sensor on the battery negative terminal, or charging voltage that varies a lot while driving. Check the owner’s manual or ask the vehicle maker. (see What is a smart alternator and how does it affect accessories?)

    Q: Does a DC-DC charger need solar? A: No. Solar input is an option on many units. It’s useful if you camp for several days without driving.

    Q: Where should the DC-DC charger go? A: Usually close to the auxiliary battery, with heavy cable from the vehicle side. Follow the maker’s limits on heat and mounting.

    Sources

    1. REDARC, “Choosing the right charger for a dual battery system” – isolators connect on sensed voltage and rely on alternator output; DC-DC chargers set the charge to suit the battery and handle voltage drop to a canopy better; isolators generally suit older fixed-voltage vehicles, DC-DC chargers newer variable-voltage ones; solar input. https://www.redarcelectronics.com/au/discover/choosing-the-right-charger-for-a-dual-battery-system/ (checked October 2026)
    2. REDARC, “BCDC v DC-DC dual battery chargers” – variable-voltage (smart) alternators need a DC-DC charger for the auxiliary battery; chemistry-specific charge profiles including lithium; solar charging. https://www.redarcelectronics.com/au/discover/bcdc-v-dcdc-dual-battery-chargers/ (checked October 2026)

  • How do I clean corroded battery terminals?

    Quick answer

    Wear gloves and safety glasses, disconnect the negative terminal first and then the positive, and scrub the white, blue or green deposits off the posts and clamps with a battery terminal brush. A solution of bicarbonate of soda (bicarb) and water helps neutralise acid residue. Rinse with a little clean water, dry everything, reconnect positive first and negative last, then protect the terminals with a terminal spray or grease. If the corrosion keeps coming back, have the battery and charging system checked.

    Is this a DIY job?

    • Difficulty: Easy
    • Time: 15 to 30 minutes
    • Tools: battery terminal brush (or a stiff wire brush), spanner (often 10 mm), bicarb soda, water, old toothbrush, rags, gloves, safety glasses
    • Skills: basic hand tools

    Step by step

    1. Protect yourself. Wear gloves and safety glasses. The deposits contain acid residue. Take off rings and metal watch bands.
    2. Check your manual. Note any radio code or reset steps, and whether your car needs special care when the battery is disconnected. (see How do I replace a car battery?)
    3. Switch everything off. Ignition off, key out.
    4. Disconnect the negative (−) terminal first, then the positive (+). Tuck the clamps away from the posts.
    5. Mix a cleaning solution. About a tablespoon of bicarb soda in a cup of warm water is a common home mix.
    6. Scrub the clamps and posts. Dip the brush in the solution and scrub. Fizzing means the bicarb is reacting with acid residue; keep applying until the fizzing stops, which tells you the acid has been neutralised. Use the terminal brush’s post end on the battery posts and the clamp end inside the clamps. If the battery has removable vent caps, make sure they’re fitted tightly first, and don’t let solution run into the cells.
    7. Rinse and dry. Wipe with a rag dampened in clean water, then dry thoroughly. Keep runoff away from paint and wiring where you can, and rinse any splashes off the paint.
    8. Check the cables. Pull back the boot on each clamp. If the copper under the insulation is green or the cable is stiff and swollen, the corrosion has spread up the cable and the cable or clamp should be replaced.
    9. Reconnect positive (+) first, then negative (−) last. Tighten firmly, but don’t over-tighten soft lead posts.
    10. Protect the terminals. Spray with terminal protector or apply a thin coat of terminal grease.
    11. Start and check. Start the car and check for warning lights. Reset radio, clock and windows if needed.

    Why bicarb soda works

    Most terminal corrosion on a lead-acid battery comes from battery acid getting out. When a battery is overcharged or runs hot, the acid inside can boil and vent, and the acid that escapes settles on the terminals and clamps and eats into them. Bicarb soda is a mild alkali. It reacts with the acid residue and turns it into harmless salts, water and carbon dioxide (the fizz), so the residue is inert and can be wiped and rinsed away safely. Scrubbing alone moves the acid around; bicarb neutralises it.

    If the battery has boiled acid out, cleaning fixes the symptom, not the cause. Have the charging system checked, because a high charging voltage will keep boiling the battery.

    Specs table

    What the corrosion is telling you

    What you see What it usually means
    Light white or grey powder Normal minor corrosion from acid vapour; clean and protect
    Heavy build-up that keeps returning Battery venting or leaking; possible overcharging; get battery and charging tested
    Green corrosion on clamps and up the cable Copper corrosion; clean and check whether the cable or clamp needs replacing
    Wet or crusty battery case, swelling Leaking or failing battery: replace it
    Corrosion and slow cranking or flickering lights Corrosion is likely causing a poor connection

    What you’ll need

    • battery terminal brush
    • battery terminal protector spray or terminal grease
    • battery terminal clamp (if a clamp is damaged)
    • battery cable (if corrosion has spread up the cable)
    • safety glasses and nitrile gloves

    When to call an auto electrician

    • Corrosion has spread under the cable insulation, or cables are swollen or brittle.
    • Corrosion comes back quickly. The battery may be leaking, or the charging voltage may be too high. (see How do I know if my alternator needs replacing?)
    • The battery case is swollen, cracked or wet, or smells of rotten eggs.
    • Your car needs battery registration or has a battery sensor on the negative terminal that might be damaged.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

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    Related questions

    Q: Can I clean battery terminals without disconnecting them? A: It’s safer to disconnect them. A brush or spanner bridging the positive terminal to metal can cause a dangerous short. Disconnecting also lets you clean the contact surfaces properly.

    Q: Can I use Coca-Cola to clean battery terminals? A: It’s a popular trick, but it leaves sticky residue. Bicarb soda and water neutralise acid and rinse off cleanly.

    Q: What causes battery terminal corrosion? A: Battery acid escaping and reacting with the metal posts and clamps. A little acid vapour causes light corrosion; heavy corrosion usually means the battery has been overcharged or overheated and boiled acid out. A leaking case or loose terminals can make it worse.

    Q: Will corroded terminals stop my car starting? A: Yes. Corrosion adds resistance, which can cause slow cranking, clicking or no start at all. (see Is it my starter motor or my battery?)

    Sources

    1. RACV, “Car battery replacement” – battery management systems and registration on some vehicles. https://racv.com.au/on-the-road/roadside-assistance/car-battery-replacement.html (checked October 2026)
    2. Planet Ark, Recycling Near You, “Recycling lead-acid batteries” – lead-acid batteries are hazardous; disposal guidance. https://recyclingnearyou.com.au/car-batteries (checked October 2026)
    3. Rolls Battery, “Cleaning – batteries and terminals” – baking soda and water solution for cleaning, vent caps closed first, rinse with water, wire-brush terminals and re-apply protective grease. https://support.rollsbattery.com/en/support/solutions/articles/646-cleaning-batteries-terminals (checked October 2026)
    4. Technical review, Ozautoelectrics (October 2026) – bicarb soda reacts with acid residue from batteries that have boiled acid out, neutralising it so it no longer corrodes the terminals. Consistent with standard acid–base chemistry (sodium bicarbonate + sulphuric acid → sodium sulphate, water and carbon dioxide).

  • How do I change my headlight globe?

    Quick answer

    Find the globe type in your owner’s manual (for example H4, H7 or H11), switch the lights off and let the globe cool, then reach in behind the headlight, remove the dust cover, release the clip or twist the globe out, and fit the new one without touching its glass. On many cars it’s a 10-minute job, but some modern cars need the bumper or headlight removed, and LED or HID headlights are a different job.

    Is this a DIY job?

    • Difficulty: Easy on many cars; Pro on cars that need the bumper, wheel arch liner or headlight unit removed
    • Time: 10 to 30 minutes when the globe is reachable
    • Tools: owner’s manual, clean gloves or a lint-free cloth, torch, sometimes a screwdriver or trim tool
    • Skills: working by feel in a tight space

    Open the bonnet and look behind the headlight before you buy anything. If you can see a round rubber or plastic cover on the back of the headlight and reach it with your hand, it’s usually a DIY job. If the back of the headlight is hidden behind the battery, air box or bumper, check the manual. It may say to remove other parts first, which is often a job for a workshop.

    Step by step

    1. Find the right globe. Look in the owner’s manual under “bulbs” or “lamps”. It lists each globe by type (e.g. H4, H7, H11, HB3, HB4). You can also read the type printed on the base of the old globe once it’s out.
    2. Check what kind of headlights you have. If your car has LED headlights or HID (xenon) headlights from the factory, stop here and read “When to call an auto electrician”. Many LED headlights don’t have a replaceable globe at all.
    3. Switch off and let it cool. Turn the headlights and ignition off. Halogen globes get very hot. Give them a few minutes.
    4. Open the bonnet and find the back of the headlight. You’re looking for a round dust cover on the back of the headlight housing, one for each globe position. The manual shows which cover is low beam and which is high beam.
    5. Make room if needed. On some cars you need to unclip the air intake duct or move the coolant reservoir aside. Only move parts the manual says to move.
    6. Remove the dust cover. Twist it anticlockwise or pull the rubber cover off.
    7. Unplug the globe. Pull the wiring connector straight off the back of the globe. Don’t pull on the wires themselves.
    8. Release the globe. Some globes are held by a wire spring clip: push it in and sideways to release it. Others twist out (usually anticlockwise) or have a locking ring. Note the way the old globe sits, including the tabs on its base.
    9. Fit the new globe without touching the glass. Hold it by the metal or plastic base. Skin oil on halogen glass creates a hot spot that can shorten its life or crack it. If you do touch it, wipe the glass with a lint-free cloth and a little methylated spirits or isopropyl alcohol and let it dry.
    10. Seat it the same way round. The tabs only fit one way. Make sure it sits flat before you refit the clip or twist it home. A globe that’s crooked will give a poor beam.
    11. Reconnect the plug and refit the dust cover. A missing or loose cover lets in water and dust.
    12. Test it. Check low beam and high beam on both sides. Then check the aim against a wall at night: if the new globe’s beam sits noticeably higher or lower than the other side, it probably isn’t seated properly.
    13. Consider doing both sides. Globes on both sides age at the same rate, so when one fails the other often isn’t far behind. Replacing them as a pair also keeps the light colour and brightness even.

    Specs table

    Common halogen headlight globe types (12V)

    Type Filaments Typical wattage Base Usually used for
    H4 2 (high and low beam in one globe) 60/55 W P43t Low and high beam in one headlight position
    H7 1 55 W PX26d Low beam or high beam (one function per globe)
    H11 1 55 W PGJ19-2 Low beam or fog lights
    HB3 (9005) 1 60 W P20d High beam
    HB4 (9006) 1 51 W P22d Low beam or fog lights

    Which globe goes where depends on the vehicle. Always confirm in your owner’s manual or from the old globe. Don’t fit a higher-wattage globe than specified: it can overheat the headlight and wiring.

    What you’ll need

    • H4 headlight globe / H7 headlight globe / H11 headlight globe (whichever your manual specifies; buy a pair)
    • nitrile gloves
    • dielectric grease (optional, a smear on the connector terminals helps keep moisture out)

    When to call an auto electrician

    • The manual says to remove the bumper, wheel arch liner or headlight unit to reach the globe.
    • Your car has factory LED headlights. Many are sealed units with no replaceable globe, and some have control modules.
    • Your car has HID (xenon) headlights. The igniter produces a very high voltage when the light switches on. Leave these to a professional.
    • The new globe doesn’t work, works only on one beam, or blows again quickly. That points to a wiring, connector, relay or control module fault.
    • A warning light or “lamp failure” message stays on after the change. Some cars with CAN-bus lighting systems are sensitive to the type of globe fitted.
    • The headlight lens is full of water or condensation that doesn’t clear.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

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    Related questions

    Q: Why does my new headlight globe not work? A: Check it’s seated properly and the connector is fully on. Then check the fuse, and test the old globe in the other side if you can. If it still doesn’t work, the fault is probably in the wiring, relay or switch. (see How do I check and replace a blown fuse?)

    Q: Should I replace headlight globes in pairs? A: It’s a good idea. Both globes have done the same hours, and matching globes give an even colour and beam on both sides.

    Q: Can I fit brighter or LED globes? A: Halogen “performance” globes of the same type and wattage are designed as direct replacements. LED retrofit globes in halogen headlights raise legal and glare questions; that topic has its own article. Never fit a higher-wattage globe than your headlight is designed for.

    Q: Why do my headlights seem dim? A: Old globes dim with age, and cloudy or yellowed lenses cut light output. Poor earths and low charging voltage can also make lights dim.

    Q: Is it illegal to drive with one headlight out? A: A headlight that doesn’t work on high or low beam is a reason to reject a vehicle at a roadworthy inspection, and police can issue a defect notice or a fine. Penalties vary by state. Replace a failed globe as soon as you can.

    Sources

    1. HELLA, “Halogen bulbs” product information (2026) – 12V wattages and bases for H4 (60/55 W, P43t), H7 (55 W, PX26d) and H11 (55 W, PGJ19-2). https://www.hella.com/forvia-us/assets/documents/BI_Halogen_Bulbs_2026.pdf (checked October 2026)
    2. NARVA, “12V HB3 60W P20d halogen headlight globe” – HB3 rating and base. https://www.narva.com.au/products/48005 (checked October 2026)
    3. NARVA, “12V 51W P22d (9006) HB4A halogen globe” – HB4 rating and base. https://narva.com.au/products/narva-12v-51w-p22d-9006-hb4a-halogen-globe-box-of-1 (checked October 2026)
    4. NARVA, “How to replace a headlight globe” – let the globe cool, don’t touch the glass, check the manual for the globe type, replace in pairs. https://narva.com.au/narva-university/blogs/how-to-replace-a-headlight-globe (checked October 2026)
    5. NARVA, “Headlight globes – tech talk” – H4 is twin-filament, others single; higher-wattage globes than specified can damage wiring and the headlight; globe categories come from UN Regulation 37. https://narva.com.au/narva-university/blogs/headlight-globes-tech-talk (checked October 2026)
    6. Transport Tasmania, “Light Vehicle Inspection Manual – Reasons for Rejection” (V23) – a high or low beam headlamp that doesn’t work is a reason for rejection. https://transport.tas.gov.au/__data/assets/pdf_file/0011/402698/Light_Vehicle_Inspection_Manual_-Reasons_for_Rejection-_V23.PDF (checked October 2026)

  • Do I need a vehicle-specific towbar wiring harness?

    Quick answer

    On most modern vehicles, yes, it’s the safer choice. Many current cars and utes monitor the current in each rear light circuit and use it to detect bulbs and trailers. Splicing trailer wiring into the tail-light loom can trigger warnings, upset trailer detection features and risk damaging the body control module. A vehicle-specific harness plugs into the factory connectors without cutting, and usually includes a trailer module that powers the trailer lights separately. Older vehicles without electronic lamp monitoring can often use a universal kit.

    Is this a DIY job?

    • Difficulty: Medium (plug-in harness); Pro (vehicles needing coding or a module install behind trim)
    • Time: 1 to 2 hours for a plug-in harness
    • Tools: trim tools, socket set, multimeter or trailer tester, cable ties
    • Skills: removing boot or tray trim, routing wiring neatly

    How the options differ

    Option How it works Suits
    Vehicle-specific (plug-and-play) harness Plugs into factory tail-light connectors with matching plugs; a module reads the signals and drives the trailer lights from its own fused battery feed Most vehicles with CAN-bus or monitored lighting
    Universal kit with isolating module Taps into lamp wires; a module isolates the trailer load from the vehicle circuits Some vehicles, where the harness maker says it’s suitable
    Direct splice Trailer wires joined straight to tail-light wires Older vehicles without lamp monitoring only

    Step by step

    1. Check what your vehicle needs. Look in the owner’s manual, the towbar maker’s fitting guide or ask the harness supplier. Some vehicles also need a dealer or scan-tool setting to enable trailer mode.
    2. Choose the right harness. Match make, model, year and body type. Check whether it includes a 7-pin flat or 12-pin socket, and whether it has an electric brake signal output.
    3. Disconnect the battery negative if the instructions say to.
    4. Remove the trim to reach the tail-light connectors. Keep clips and screws together.
    5. Plug the harness in-line at each tail-light connector as instructed. Don’t cut factory wiring.
    6. Mount the module where the instructions say, away from water and heat.
    7. Run the power feed from the battery, fused near the battery, if the harness needs one. Route it away from exhaust and sharp edges, using grommets through panels.
    8. Fit the socket at the towbar with its cover and seal.
    9. Test every function with a trailer tester: tail, both indicators, stop, reverse, and brake output if fitted.
    10. Check for warnings on the dash. Then refit the trim.

    Specs table

    Signs a vehicle needs a module or plug-in harness

    Sign Why it matters
    Bulb or lamp-failure warnings on the dash The vehicle monitors lamp current
    LED tail lights from the factory Very low current; often monitored
    Trailer stability or trailer-detection features May rely on detecting a connected trailer
    Owner’s manual or towbar guide calls for a specific harness Follow the maker

    What you’ll need

    • towbar wiring harness (vehicle-specific)
    • 7 pin flat trailer socket or 12 pin flat trailer socket (if not included)
    • trailer circuit tester
    • inline fuse holder (if the harness needs a battery feed and doesn’t include one)
    • split loom tube and cable ties

    When to call an auto electrician

    • No plug-in harness exists for your vehicle.
    • The vehicle needs trailer mode enabled or a module coded.
    • You also need an electric brake controller, a 12-pin auxiliary circuit or a DC-DC charger.
    • Warnings appear after fitting, or the trailer lights behave oddly.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

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    Related questions

    Q: Can I just splice into my tail lights? A: On older vehicles without lamp monitoring, a careful splice can work. On most modern vehicles it risks warnings, faults and problems with trailer detection, so a plug-in harness is the safer choice.

    Q: Does a towbar harness run electric trailer brakes? A: A lighting harness alone doesn’t. Electric brakes need a brake controller wired to pin 5. (see How do I install an electric brake controller?)

    Q: Will a towbar harness affect my warranty? A: A plug-in harness that doesn’t cut factory wiring is less likely to cause disputes than a spliced install. If you’re concerned, ask your dealer before fitting.

    Q: Why do my trailer lights work but the car shows a warning? A: The vehicle may be detecting an unexpected load on its lamp circuits. That usually means a splice or an incompatible module. Have it checked.

    Sources

    1. EV Parts 4×4, “GWM Cannon trailer wiring: dedicated vs universal” – example of a body control module monitoring lamp current; risks of splicing; plug-in harness with module (vendor article, one vehicle example). https://evparts4x4.com/blogs/featured-articles/gwm-cannon-trailer-wiring-dedicated-vs-universal (checked October 2026)
    2. Department of Infrastructure, VSB 1 Revision 5 – trailer connectors to AS 2513 or AS 4177.5; pin 5 of a 7-pin connector recommended for service brakes only. https://www.infrastructure.gov.au/sites/default/files/documents/vehicle-standards-bulletin-1-revision5-trailers-with-an-aggregate-trailer-mass-of-4-5-tonnes-or-less-june2009-pdf.pdf (checked October 2026)
    3. ARB, Hayman Reese CAN ECU module for towing systems – modern vehicles use CAN-bus networks, and a module manages trailer light and brake signals without upsetting vehicle systems or triggering dash warnings (manufacturer product page). https://www.arb.com.au/product/twle70029-hayman-reese-can-ecu-module-for-towing-systems (checked October 2026)

  • What should I do if I smell burning plastic or see smoke from my car’s wiring?

    Quick answer

    Pull over somewhere safe, switch off the ignition, put it in Park with the handbrake on, and get everyone out and well away from the car. If you see flames, or the smoke keeps coming, call Triple Zero (000) and don’t lift the bonnet. Don’t drive the car again, or reconnect anything, until an auto electrician has found and fixed the cause.

    Is this a DIY job?

    • Difficulty: Pro only
    • Time: Your part takes minutes: get safe, then arrange a tow
    • Tools: phone; a vehicle fire extinguisher only if you already carry one and feel confident using it
    • Skills: none: this is about staying safe, not repairing

    A burning plastic smell or smoke from wiring means something is overheating: a short circuit, a failed component, a loose high-current connection, or wiring that has rubbed through or been chewed. Any of these can start a fire. Finding the cause takes the right test equipment and wiring information, so leave the diagnosis and repair to a professional. This article covers only what you should do.

    Step by step: what to do right now

    1. Pull over safely. Indicate, get off the road as soon as it’s safe and stop away from dry grass, buildings, fuel bowsers and other cars.
    2. Ignition off. Turn the engine off, put the car in Park (or in gear for a manual) and apply the handbrake.
    3. Get everyone out. Get all passengers out, including children and pets, and move well away from the car, to the side away from traffic. Take your phone. Leave belongings behind.
    4. Don’t breathe the smoke. Burning plastic gives off toxic fumes. Stay upwind if you can.
    5. Call 000 if there’s fire. If you see flames, or the smoke is increasing, call Triple Zero (000) and ask for the fire service. Tell them where you are and, if relevant, that the car is a hybrid, EV or runs on LPG.
    6. Don’t lift the bonnet if there are flames. Opening the bonnet lets in a rush of air that can make a fire flare up and cause serious burns.
    7. Use an extinguisher only if it’s safe. Only if you carry one and feel confident. Fire Rescue Victoria’s advice for a fire under the bonnet is to release the bonnet catch but not lift the bonnet, and aim the extinguisher through the gap. For a fire in the cabin, aim it at the fire and then close the door. If in doubt, stay back and wait for firefighters.
    8. LPG cars: turn off the gas at the main valve, but only if you know where it is and can reach it safely.
    9. If there are no flames and the smoke has stopped, stay away from the car for a while and watch it from a safe distance. Wiring can keep smouldering after you switch off.
    10. Disconnect the battery only if it’s safe. Only once there are no flames, the smoke has stopped and nothing is hot to touch. Remove the negative terminal first, then the positive, and tuck both leads away from the posts. Don’t do this on a hybrid or EV: their high-voltage systems are professional only. If you’re not sure, leave it.
    11. Don’t restart or reconnect. Don’t start the car “to see if it happens again” and don’t reconnect the battery. The fault is still there.
    12. Arrange a tow. Have the car taken to an auto electrician or workshop rather than driving it.
    13. Tell your insurer if there was any fire damage.
    14. Check for recalls. Some vehicles have been recalled because of wiring or component fire risks. You can search by make and model on the Australian Government’s vehicle recalls website (see Sources).

    Hybrids and electric vehicles

    Hybrids and EVs have high-voltage batteries and wiring (usually in orange covering) as well as the normal 12V system. Never touch high-voltage parts, cut cables or disconnect anything on these cars after smoke or a fire. Fire Rescue Victoria warns that a damaged EV battery can catch fire hours, days or even weeks after the event, and advises keeping a damaged EV in the open, at least 15 metres from other vehicles, buildings and anything that can burn. If the battery itself is smoking or burning, call 000 and wait somewhere safe.

    Specs table

    What to do in each situation

    What you notice What to do
    Flames anywhere Get everyone out and away, call 000, don’t lift the bonnet
    Smoke from under the bonnet or dash, no flames Pull over, ignition off, everyone out, call 000 if it keeps coming or gets worse
    Burning plastic smell, no smoke Pull over, ignition off, get out and check from outside; don’t keep driving
    Smell comes back each time you use one accessory Stop using it, pull the accessory’s fuse if you can reach it safely, book an inspection
    Rotten egg smell near the battery Battery may be overcharging or failing; keep away from sparks and flames
    Smoke or smell on a hybrid or EV Everyone out and away; call 000 if smoking or burning; don’t touch high-voltage parts

    Fire extinguisher for a vehicle

    Item Fire Rescue Victoria advice
    Type Dry powder portable extinguisher rated 1A 5B(E)
    Where Somewhere easily reached in the vehicle

    What you’ll need

    This isn’t a DIY repair, so there are no parts to buy for the fix. To be prepared:

    • vehicle fire extinguisher dry powder with a mounting bracket
    • battery isolator switch: turning it off cuts the battery off from the whole vehicle in seconds, without spanners. It also stops small background current draws from flattening the battery while the vehicle is parked for long periods, which makes it popular on 4WDs, caravans, boats and vehicles that sit unused. Have an auto electrician fit it, because it carries the full starter current.

    Commercial and mining vehicles. Some vehicles must carry an extinguisher by law or by site rules:

    • Vehicles carrying a placard load of dangerous goods must carry fire extinguishers under the Australian Dangerous Goods Code (chapter 12). The number and size depend on the load, from one 2 kg dry chemical powder extinguisher for packaged goods up to larger units in the load area for bulk flammable goods.
    • Mine sites set their own requirements for light vehicles and mobile plant, and commonly require an extinguisher in every vehicle. Check the site’s rules before you go on site.

    Browse vehicle fire extinguishers on Ozautoelectrics.

    When to call an auto electrician

    Always, after any burning smell or smoke from wiring. In particular:

    • You’ve had smoke, melted wiring or a blown fuse that keeps blowing.
    • The smell started after an accessory was fitted (driving lights, a dashcam, a dual battery, a stereo or a towbar harness).
    • You’ve found signs of rodent damage under the bonnet. (see Have rats or mice chewed my car wiring?)
    • The car has been in a flood or had water inside.
    • The car is a hybrid or EV. High-voltage systems are professional only.
    • Airbag/SRS wiring is involved (under the seats, in the steering wheel or dash). Airbag work is professional only.

    Ask for the car to be towed rather than driven. Fire Rescue Victoria advises not driving a car after a fire until an auto electrician or qualified mechanic has checked it.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

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    Related questions

    Q: Is it safe to drive with a burning plastic smell? A: No. Pull over, switch off and get out. A burning plastic smell usually means something electrical is overheating, and wiring can catch fire with little warning.

    Q: Should I disconnect the battery after smoke from wiring? A: Only if there are no flames, the smoke has stopped and you can do it safely. Remove the negative terminal first. Never disconnect anything on a hybrid or EV’s high-voltage system.

    Q: Why shouldn’t I open the bonnet if there’s a fire? A: Lifting the bonnet lets a rush of air reach the fire, which can make it flare up and cause serious burns. Call 000 and stay back.

    Q: What causes car wiring to burn? A: Common causes include short circuits, poor connections that heat up under load, wiring rubbed through on metal edges, rodent damage, water damage, and accessories wired with cable that’s too thin or not fused properly. (see What size cable do I need for my 12V accessory?)

    Q: Can I just replace the melted wire myself? A: It isn’t recommended. The melted wire is usually a symptom, not the cause. Unless the original fault is found, it can happen again.

    Sources

    1. Fire Rescue Victoria, “Vehicles and boats” – what to do if a vehicle catches fire: ignition off, Park and handbrake, get out, call 000; release the bonnet catch only and don’t lift the bonnet; toxic smoke from burning plastics; remove battery leads after the fire is out if safe; don’t drive until checked by an auto electrician or qualified mechanic; 1A 5B(E) dry powder extinguisher; damaged EV batteries may ignite hours, days or weeks later; keep damaged EVs at least 15 m from other vehicles and buildings. https://frv.vic.gov.au/vehicles-and-boats (checked October 2026)
    2. Australian Government, Vehicle Recalls (Department of Infrastructure, Transport, Regional Development, Communications and the Arts listed as regulator) – searchable vehicle recalls, including wiring and component fire risks. https://www.vehiclerecalls.gov.au/ (checked October 2026)
    3. National Transport Commission, “Australian Dangerous Goods Code Review – Discussion Paper 5: Fire Extinguishers” – ADG Code chapter 12 (12.1.2, Table 12.1): fire extinguisher requirements for road vehicles carrying placard loads. https://www.ntc.gov.au/sites/default/files/assets/files/Australian%20Dangerous%20Goods%20Code%20Review%20-%20Discussion%20Paper%205%20-%20Fire%20Extinguishers.pdf (checked October 2026)

  • How do I crimp automotive wire connectors properly?

    Quick answer

    Pick a terminal sized for your cable’s copper area in mm² (not its “mm” label), strip just enough insulation to fill the terminal barrel, and crimp it with a ratchet crimper using the die that matches the terminal. A good crimp passes a hard tug test without the wire moving. Finish with adhesive-lined heat shrink wherever the joint will see water, dust or vibration.

    Is this a DIY job?

    • Difficulty: Easy
    • Time: 2 to 5 minutes per terminal once you’re set up
    • Tools: ratchet crimper with the right dies, wire stripper, side cutters, heat gun
    • Skills: none beyond care and patience; practise on offcuts first

    Crimping is one of the most useful skills for any 12V job, and a good tool does most of the work. Leave it to a professional if the terminals are part of a factory loom connector, an airbag circuit, or anything high-current like starter or winch cables.

    Step by step

    1. Make it safe. If the wire is connected to anything live, pull the circuit’s fuse or disconnect the battery first: negative off first, and negative back on last when you’re done.
    2. Check the cable size in mm². Read the printing on the cable, or check the reel. Australian auto cable sold as “3mm” has about 1.13 mm² of copper, “4mm” about 1.84 mm² and “6mm” about 4.59 mm². (see What size cable do I need for my 12V accessory?)
    3. Choose a terminal that suits that copper area. Insulated terminals are colour-coded by wire range (see the table below). For a sealed, tidy job, choose terminals with a nylon sleeve or plan to use heat shrink. Use stranded auto cable; solid-core wire isn’t suited to crimp terminals.
    4. Slide on the heat shrink first. It’s easy to forget, and once the terminal is on you can’t add it.
    5. Strip the insulation. Remove only enough to fill the metal barrel of the terminal. Use a stripper set to the right size so you don’t cut or nick strands. Twist the strands lightly so none stray.
    6. Insert the wire. Push the bare copper fully into the barrel. On an insulated terminal, the end of the insulation should sit just inside the plastic sleeve. On an open-barrel (non-insulated) terminal, the copper sits under the larger front tabs and the insulation sits under the smaller rear tabs, with a few strand ends just visible past the front tabs.
    7. Use the matching die. Put the terminal in the die that matches its colour or size. Insulated terminals and open-barrel terminals need different dies; one die won’t do both properly.
    8. Crimp in one full stroke. Squeeze the ratchet crimper until it releases by itself. The ratchet stops you letting go half way, which is the most common cause of loose crimps.
    9. Tug test it. Hold the terminal and pull the wire firmly. It must not slide, rotate or pull out. If it moves, cut it off and start again; don’t re-crimp the same terminal.
    10. Inspect it. You shouldn’t see loose strands outside the barrel, insulation trapped under the copper crimp, or a cracked sleeve.
    11. Seal it. Slide the adhesive-lined heat shrink over the barrel and onto the cable insulation, then heat it evenly until it shrinks and a little adhesive shows at each end.
    12. Restore power and test. Refit the fuse or reconnect the battery (negative last) and check the circuit works.

    Specs table

    Insulated terminal colours and Australian auto cable

    The colour code on insulated crimp terminals is widely used across makers. Always check the wire range printed on the packet.

    Terminal colour Wire range Australian auto cable that fits
    Red 0.5 to 1.5 mm² 3mm auto cable (1.13 mm²)
    Blue 1.5 to 2.5 mm² 4mm auto cable (1.84 mm²)
    Yellow 4 to 6 mm² 5mm (2.90 mm²) and 6mm (4.59 mm²) auto cable

    Note: 5mm auto cable (2.90 mm²) is too big for blue terminals, so auto electricians use yellow. It sits at the small end of the yellow range, so use a good ratchet crimper on the yellow die and always pull-test the crimp firmly. Some terminal makers print a wider yellow range, so check the packet.

    Heavier cable (8 B&S and up) uses tubular copper lugs crimped with a hex or hydraulic lug crimper, not these terminals.

    How strong is a good crimp?

    For reference, the UL 486A standard sets minimum pull-out forces for crimped terminals. A good crimp should comfortably beat a firm hand tug.

    Wire size Approx. copper area UL 486A minimum pull-out
    18 AWG 0.82 mm² 89 N (about 9 kg)
    16 AWG 1.31 mm² 133 N (about 13.6 kg)
    14 AWG 2.08 mm² 222 N (about 22.7 kg)
    12 AWG 3.31 mm² 311 N (about 31.8 kg)

    These figures are a guide to how much a sound crimp should hold. A home tug test can’t measure them, but a crimp that pulls out by hand is well short.

    What you’ll need

    • ratchet crimper insulated terminals
    • ratchet crimper non-insulated terminals (if you use open-barrel terminals)
    • automatic wire stripper
    • insulated crimp terminal kit
    • heat shrink crimp terminals (for wet or exposed locations)
    • adhesive lined heat shrink
    • heat gun
    • auto cable (sized for the job)

    When to call an auto electrician

    • The terminals are inside a factory connector plug. These need the correct pin, seal and often a dedicated crimp tool.
    • The wiring is near airbags, seatbelt pretensioners or their yellow looms. Airbag (SRS) wiring is professional-only.
    • The vehicle is a hybrid or electric vehicle and the cable is orange. High-voltage systems are professional-only.
    • You need to terminate heavy battery, starter, winch or inverter cable.
    • A crimped joint is getting hot, discoloured or causing a fault that comes and goes.

    Need an auto electrician? Find local auto electricians and mobile services in your city.

    Find an auto electrician near you

    Related questions

    Q: Can I crimp terminals with pliers? A: You can squash a terminal with pliers, but it won’t compress evenly and often loosens with vibration. A ratchet crimper with the right die makes a consistent crimp every time.

    Q: Should I solder a crimp as well? A: It depends on the job. Many auto electricians see a soldered and crimped joint as the best for conductivity and long life, but a correct crimp made with the right tool is reliable on its own for most jobs. If you do solder, keep the solder to the crimped area and support the cable behind the terminal, because solder that wicks up the strands makes a stiff spot where vibration can crack the wire. Sealed connectors such as Deutsch use solid contacts with a four-indent crimp and normally aren’t soldered.

    Q: What does the colour on a crimp terminal mean? A: It shows the wire size the terminal suits: red for 0.5 to 1.5 mm², blue for 1.5 to 2.5 mm² and yellow for 4 to 6 mm².

    Q: Do I need heat shrink over crimp terminals? A: Inside the cabin it’s optional on insulated terminals. Under the bonnet, under the vehicle, on a trailer or anywhere wet, adhesive-lined heat shrink keeps water and corrosion out of the joint.

    Q: How do I connect a new accessory to power safely? A: Run it from a fused source, with the fuse close to the battery and rated to protect the cable. (see Where should the fuse go when wiring an accessory?)

    Sources

    1. RS Components (RND Connect), insulated crimp terminal datasheet – colour code red 0.5–1.5 mm² (22–16 AWG), blue 1.5–2.5 mm² (16–14 AWG), yellow 4–6 mm² (12–10 AWG). https://docs.rs-online.com/c5cd/A700000013591123.pdf (checked October 2026)
    2. Tycab, automotive cable catalogue – single-core auto cable stranding and copper areas (14/0.32 1.13 mm², 23/0.32 1.84 mm², 36/0.32 2.90 mm², 57/0.32 4.59 mm²). https://www.tyree.nz/wp-content/uploads/2019/09/Automotive-Comp.pdf (checked October 2026)
    3. Molex, “Introduction to Crimp Technology” (application tooling) – parts of a crimp (conductor crimp, insulation crimp, bellmouth, conductor brush), common defects, pull testing. https://www.molex.com/content/dam/molex/molex-dot-com/en_us/pdf/general/987652-5181.pdf (checked October 2026)
    4. NASA, NASA-STD-8739.4A “Workmanship Standard for Crimping, Interconnecting Cables, Harnesses, and Wiring” – stranded wire for crimped contacts; full-cycle ratcheting crimp tools; pull testing. https://nepp.nasa.gov/files/27631/nstd87394a.pdf (checked October 2026)
    5. Cirris, “Crimp pull testers: pullout force per wire size” – summary of UL 486A minimum pull-out forces for terminals (18 AWG 20 lbf, 16 AWG 30 lbf, 14 AWG 50 lbf, 12 AWG 70 lbf; converted to newtons and kg). https://cirris.com/crimp-pull-testers-pullout-force-per-wire-size/ (checked October 2026)
    6. AWG to mm² conversions (18 AWG 0.82 mm², 16 AWG 1.31 mm², 14 AWG 2.08 mm², 12 AWG 3.31 mm²) – standard American Wire Gauge definitions.
    7. Hella, heat shrink insulated crimp terminal connectors – red, blue and yellow terminals, with yellow for 4 to 6 mm² cable. https://www.hella.co.nz/en/products/accessories/connectors/heat-shrink-insulated-crimp-terminal-connector.html (checked October 2026)
    8. Wiltronics, 4mm twin core auto cable – “4mm” auto cable is 23/0.32 stranding (about 1.85 mm²). https://www.wiltronics.com.au/product/52830/4mm-twin-core-auto-cable (checked October 2026)