Category: Lighting

  • 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.

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    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 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.

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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)

  • How do I replace an indicator globe?

    Quick answer

    If one side’s indicator suddenly flashes fast, a globe on that side has usually blown. Find the globe type in your owner’s manual (often PY21W, P21W or WY5W), reach the globe holder from behind the lamp, twist it out, fit the new globe and test before you put everything back. Front indicators on some modern cars are reached through the wheel arch or need the headlight removed.

    Is this a DIY job?

    • Difficulty: Easy (rear and side indicators); Easy to Pro (front, depending on the car)
    • Time: 10 to 30 minutes
    • Tools: owner’s manual, screwdriver or trim tool, torch
    • Skills: gentle handling of plastic clips

    Rear indicators are usually reached from the boot, the same way as the brake lights. Side repeaters on the guards often pop out with a gentle push and twist. Front indicators vary the most: some twist out from behind the headlight, some are reached through an opening in the wheel arch liner, and some need the bumper or headlight removed.

    Step by step

    Common bayonet globe bases: BA15s, BAY15d and BAU15s Three 15 mm bayonet globes. BA15s (for example P21W): two locating pins opposite each other at the same height and one contact on the bottom. BAY15d (for example P21/5W): pins at different heights and two contacts on the bottom, so it only fits one way. BAU15s (for example amber PY21W): pins at the same height but not opposite each other, and one contact. Bayonet globe bases: how to tell them apart Side view (top row) and looking at the bottom of the base (bottom row). Not to scale. BA15s Pins level, opposite BAY15d Pins at different heights BAU15s Pins level, not opposite One contact Two contacts One contact, offset pin e.g. P21W (brake, reverse) e.g. P21/5W (brake + tail) e.g. PY21W (amber indicator) Always confirm the globe code in your owner’s manual or on the old globe before buying.
    Common bayonet globe bases: BA15s, BAY15d and BAU15s
    1. Work out which globe is out. Switch on the hazard lights and walk around the car. Check front, rear and side repeaters. A blown globe usually makes the dash indicator light and the ticking flash about twice as fast on that side.
    2. Find the globe type. Check the owner’s manual. Indicators commonly use PY21W (amber glass, bayonet), P21W (clear glass, for amber lenses), or small WY5W wedge globes in side repeaters. Buy a pair.
    3. Switch off. Ignition and lights off.
    4. Rear indicator: open the boot, remove the access cover or tail light unit as your manual shows, then twist the indicator holder out (usually anticlockwise).
    5. Side repeater: many slide or push one way to release a clip, then tilt out. Don’t lever against the paint; use a plastic trim tool and a cloth. Pull the holder out of the back and replace the wedge globe.
    6. Front indicator: look behind the headlight for a holder with an amber globe. If it isn’t reachable, check the manual. Some cars have an access flap in the wheel arch liner (turning the steering wheel gives more room). If the manual says to remove the bumper or headlight, consider a workshop.
    7. Remove the old globe. Bayonet: push in, twist anticlockwise, pull out. Wedge: pull straight out.
    8. Match the colour. If the lamp lens is clear, the globe must be amber (PY21W or WY5W). If the lens is amber, a clear globe (P21W or W5W) is normally used. An indicator must show amber light.
    9. Fit the new globe. PY21W globes have offset pins and only fit one way. Don’t force them.
    10. Test before refitting. Check the indicator flashes at the normal rate on both sides, then refit the holder, covers and lamp unit with seals in place.

    Specs table

    Common indicator globe types (12V)

    Type Glass Wattage Base Typical use
    PY21W Amber 21 W BAU15s (pins offset, one contact) Front and rear indicators behind clear lenses
    P21W Clear 21 W BA15s (pins level and opposite) Indicators behind amber lenses
    WY5W Amber 5 W Wedge (W2.1×9.5d) Side repeaters behind clear lenses
    W5W Clear 5 W Wedge (W2.1×9.5d) Side repeaters behind amber lenses

    Fitment varies by vehicle. Your owner’s manual or the old globe has the correct code.

    What you’ll need

    • PY21W amber indicator globe or P21W globe (front and rear, as specified)
    • WY5W amber wedge globe or W5W wedge globe (side repeaters)
    • plastic trim tool
    • If you’re converting to LED: LED flasher relay or load resistor (see related questions)

    When to call an auto electrician

    • The front indicator needs the bumper or headlight removed.
    • A new globe doesn’t fix the fast flashing, or no indicator on one side works at all. Check the fuse, then suspect the wiring, earth or switch.
    • The indicators don’t work at all, or the hazard lights work but the indicators don’t (or the reverse). That points to the flasher, switch or body control module.
    • Your car shows a “lamp failure” or bulb warning after the change, or you’ve fitted LED globes and get warnings. Many modern cars monitor lamp current through a CAN-bus control module, and the fix depends on the vehicle.
    • The indicator lamp is a sealed LED unit.

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    Related questions

    Q: Why are my indicators flashing fast? A: Usually a globe has blown on that side. If you’ve fitted LED indicator globes, they draw so little current that the car thinks a globe is out. (see Why are my indicators flashing fast?)

    Q: Can I use a clear globe behind a clear indicator lens? A: No. The light from an indicator must be amber. Behind a clear lens you need an amber globe such as a PY21W or WY5W.

    Q: Why does my amber indicator globe look pale or flash white? A: The amber coating on cheaper globes can fade over time. Replace faded globes, because the light must still be amber.

    Q: Do I need to replace indicator globes in pairs? A: It isn’t essential, but the other side has done the same hours and often fails soon after. Replacing both keeps the colour matched.

    Sources

    1. OSRAM, PY21W product data – BAU15s base, 12 V, 21 W. https://osram.com/ecat/Lamps%20with%20metal%20bases-Signal%20lamps-Car%20lighting-Automotive/ae/en/GPS01_1057060/ZMP_60924 (checked October 2026)
    2. OSRAM, P21W product data – BA15s base, 12 V, 21 W. https://osram.com/ecat/Lamps%20with%20metal%20bases-Signal%20lamps-Car%20lighting-Automotive/gb/en/GPS01_1057060/ZMP_1285824 (checked October 2026)
    3. OSRAM, WY5W product data – W2.1×9.5d wedge base, 12 V, 5 W. https://www.osram.co.uk/ecat/gb/en/GPS01_1057061/ZMP_4057277 (checked October 2026)
    4. Federal Register of Legislation, Vehicle Standard (Australian Design Rule 13/00 – Installation of Lighting and Light Signalling Devices on other than L-Group Vehicles) 2005 – Table 1 lists direction-indicator lamps as amber. https://www.legislation.gov.au/F2005L03991/latest (checked October 2026)
    5. Federal Register of Legislation, Vehicle Standard (Australian Design Rule 6/00 – Direction Indicators) 2005 – component rule for direction indicators. https://www.legislation.gov.au/F2005L03907/latest (checked October 2026)

  • How do I replace a brake light globe?

    Quick answer

    Get someone to press the brake pedal so you can see which light is out, then open the rear lamp access panel in the boot (or remove the tail light unit, as your owner’s manual describes), twist out the globe holder and swap the globe for one of the same type, often a P21/5W or P21W bayonet or a wedge-type globe. If both brake lights and the high third brake light are out together, the problem is more likely the fuse or brake light switch than the globes.

    Is this a DIY job?

    • Difficulty: Easy
    • Time: 10 to 30 minutes
    • Tools: owner’s manual, screwdriver or trim tool (some cars), clean cloth
    • Skills: none beyond care with plastic clips

    On most cars this is a simple job from inside the boot or tailgate. Some cars need the tail light unit unbolted and pulled out, which is still a DIY job if you’re patient with the clips.

    Step by step

    Common bayonet globe bases: BA15s, BAY15d and BAU15s Three 15 mm bayonet globes. BA15s (for example P21W): two locating pins opposite each other at the same height and one contact on the bottom. BAY15d (for example P21/5W): pins at different heights and two contacts on the bottom, so it only fits one way. BAU15s (for example amber PY21W): pins at the same height but not opposite each other, and one contact. Bayonet globe bases: how to tell them apart Side view (top row) and looking at the bottom of the base (bottom row). Not to scale. BA15s Pins level, opposite BAY15d Pins at different heights BAU15s Pins level, not opposite One contact Two contacts One contact, offset pin e.g. P21W (brake, reverse) e.g. P21/5W (brake + tail) e.g. PY21W (amber indicator) Always confirm the globe code in your owner’s manual or on the old globe before buying.
    Common bayonet globe bases: BA15s, BAY15d and BAU15s
    1. Find out which light is out. Have a helper press the brake pedal while you look at both brake lights and the high-mounted third brake light. No helper? Reverse up close to a garage door or shop window at night and use your mirrors.
    2. Check the pattern. If only one brake light is out, it’s almost certainly the globe. If all brake lights are out, check the fuse and the brake light switch at the pedal before buying globes.
    3. Find the globe type. The owner’s manual lists it. Common types are P21/5W (brake and tail in one globe), P21W (brake only) and W21/5W (wedge type, brake and tail). Buy a pair.
    4. Switch everything off. Ignition off, lights off.
    5. Get to the back of the lamp. Open the boot and look for a small access cover or panel behind the tail light. Some cars instead need two or three nuts or screws undone so the whole tail light unit can be eased out. Protect the paint with a cloth.
    6. Remove the globe holder. Most holders twist anticlockwise about a quarter turn and pull out. Some are a carrier plate with several globes, released by plastic tabs.
    7. Remove the old globe. Bayonet globes: push in gently, twist anticlockwise and pull out. Wedge globes: pull straight out.
    8. Check the old globe and holder. A blackened glass or broken filament confirms the globe has failed. Look for corrosion or melted plastic in the holder. Green corrosion can be cleaned off with a small brush and contact cleaner.
    9. Fit the new globe. A P21/5W globe has offset pins so it only fits one way. Don’t force it: if it won’t go in, turn it 180 degrees. Getting it in the wrong way round isn’t possible with a correct globe, but forcing it can damage the holder.
    10. Refit the holder and test. Check the brake light, tail light and indicator on that side before you refit any covers. Then refit the unit or cover and make sure any seals sit properly so water stays out.

    Specs table

    Common rear lamp globe types (12V)

    Type Filaments Wattage Base Typical use Notes
    P21/5W 2 21/5 W BAY15d (offset pins, two contacts) Brake and tail in one globe Often sold as “1157-type”
    P21W 1 21 W BA15s (level pins, one contact) Brake only, reverse, rear fog Often sold as “1156-type”
    W21/5W 2 21/5 W W3x16q (wedge) Brake and tail in one globe US equivalent 7443
    W21W 1 21 W W3x16d (wedge) Brake only, reverse US equivalent 7440

    US 1156 and 1157 globes fit the same bases as P21W and P21/5W but aren’t identical in rating. Buy by the code in your owner’s manual where you can.

    What you’ll need

    • P21/5W globe or P21W globe or W21/5W wedge globe (whichever your manual specifies)
    • electrical contact cleaner (if the holder is corroded)
    • Spare blade fuses (if all brake lights are out)

    When to call an auto electrician

    • All the brake lights are out and the fuse is fine. The brake light switch or wiring is the likely cause, and on many cars the switch also feeds cruise control, stop-start and the engine computer.
    • The brake lights stay on all the time. That can flatten the battery and confuses drivers behind you.
    • The high-mounted third brake light has failed. On many cars it’s a sealed LED unit that’s replaced as a whole.
    • The car’s tail lights are LED units. Most can’t be repaired by changing a globe.
    • A “lamp failure” warning stays on after the change, or the new globe works dimly or flickers.
    • The holder is melted or the wiring is burnt.

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    Related questions

    Q: Is it illegal to drive with a brake light out? A: Brake lights are a required safety item. In Queensland, for example, a vehicle with a part that doesn’t work as intended counts as defective, and driving it can lead to a defect notice or fine. Check your own state’s rules. More importantly, the driver behind may not see you slow down. Replace it straight away.

    Q: Why do both my brake light and tail light share a globe? A: A P21/5W or W21/5W globe has two filaments: a dim one for the tail light and a bright one for braking. One globe does both jobs.

    Q: My new globe glows when I turn the headlights on and the indicator flashes oddly. Why? A: This often means a poor earth in the lamp unit or holder. Clean the earth connection and check the holder for corrosion.

    Q: Can I fit LED globes in my brake lights? A: Some LED replacements are available, but they can cause lamp-failure warnings on CAN-bus vehicles, and their light pattern in a reflector designed for a filament globe may not be as bright. The lamp must still meet the Australian Design Rules.

    Sources

    1. Wikipedia, “List of automotive light bulb types” – P21W, P21/5W, W21W and W21/5W bases, wattages and ANSI equivalents (7440, 7443). https://en.wikipedia.org/wiki/List_of_automotive_light_bulb_types (checked October 2026)
    2. Narva, “12V 21W P21W BA15S incandescent globe” (part 47382) – P21W is 12V 21W on a BA15s base. https://www.narva.com.au/products/47382 (checked October 2026)
    3. Narva, “12V 21/5W BAY15d globe” (part 17916BL) – 21/5W dual-filament on a BAY15d offset-pin base for stop/tail. https://www.narva.com.au/products/17916BL (checked October 2026)
    4. Queensland Government, Transport Operations (Road Use Management—Vehicle Standards and Safety) Regulation 2021, ss 7–9 – a vehicle is defective if a component doesn’t perform its intended function; offence to drive a defective vehicle; defect notices. https://www.legislation.qld.gov.au/view/whole/html/inforce/2026-07-01/sl-2021-0114 (checked October 2026)

  • Why are my indicators flashing fast?

    Quick answer

    Fast flashing (often called hyperflash) almost always means the car thinks an indicator globe on that side has failed. Usually a globe really has blown, but it also happens after fitting LED globes, because they draw so little current the system reads them as blown. Replace the blown globe; or, for LEDs, fit a flasher relay made for LEDs, add load resistors, or have the body control module recoded, keeping in mind that aftermarket LED replacement globes may not keep the lamp ADR compliant.

    Is this a DIY job?

    • Difficulty: Easy (globe replacement); Medium (load resistors or a flasher relay)
    • Time: 10 minutes to find the cause; 15 minutes to 1 hour to fix
    • Tools: owner’s manual, screwdriver or trim tool, torch, multimeter for wiring checks
    • Skills: replacing a globe; basic wiring for resistors

    Finding and replacing a blown globe is a simple DIY job. If the car uses a body control module to run the indicators, or the fix involves coding, it’s a job for an auto electrician with the right scan tool.

    Why it happens

    Australian vehicles must have indicators that flash between 60 and 120 times a minute (90 ± 30). If one globe fails, the design rules require the others to keep flashing, and the driver’s tell-tale must show there’s a problem: by going out, staying on steady, or changing rate. Many vehicles do it by flashing fast.

    On older cars, the flasher unit senses the current drawn by the globes. Lose one globe’s worth of current and the flasher speeds up. On newer cars, the body control module measures the current in each indicator circuit and does the same job. Either way, an LED globe that draws a fraction of the current of a 21 W globe looks like a blown globe.

    Step by step

    1. Switch on the hazard lights. Walk around the vehicle and check every indicator: front, rear, side repeaters, and any trailer lights if one is connected.
    2. Note which side flashes fast. Usually it’s only one side. That points to a globe, globe holder or wiring fault on that side.
    3. Replace any globe that’s out. Use the type listed in the owner’s manual, and match amber to amber. (see How do I replace an indicator globe?)
    4. If every globe lights, look closer. A globe that glows dimly, a corroded globe holder, or a poor earth on that side can reduce the current and cause fast flashing. Clean the holder and check the earth.
    5. Check for a trailer fault. If it only happens when the trailer is plugged in, the problem is usually a trailer globe, plug or earth. (see Why aren’t my trailer lights working?)
    6. If you’ve fitted LED indicator globes, that’s likely the cause. Choose one of the fixes below, or go back to the original filament globes.
    7. If both sides flash fast, or the rate changes at random, suspect the flasher relay or a body control module fault, especially after other electrical work. Have it scanned.

    Fixing fast flashing after fitting LED globes

    Option 1: an LED flasher relay. On older vehicles with a plug-in flasher relay, swap it for an electronic flasher designed for LEDs. It flashes at the normal rate whatever the load. Match the pin layout and number of pins to your original flasher. Be aware it may also stop the indicators warning you when a globe really fails.

    Option 2: load resistors. On many modern vehicles, load resistors are essential when fitting LED globes. These vehicles sense the current in the indicator circuit, and without the extra load they show an indicator warning, flash fast, or don’t work normally. A load resistor is wired across each LED globe, from the indicator wire to earth, so the circuit draws about the same current as the original globe. One resistor is needed for each globe replaced. Load resistors work by turning that extra current into heat: one 12V resistor designed to stand in for a 21 W globe is rated by its maker to reach up to 170°C. Mount every resistor on bare metal, away from plastic, carpet, paint and wiring, and never leave one loose in a lamp housing or behind trim. Note that once you’ve added resistors, much of the LED’s power saving is gone.

    Option 3: coding the body control module. On many modern vehicles the indicators are run by the body control module, and there’s no flasher relay to change. Some vehicles can be recoded with a scan tool to accept LED globes; others can’t, and adding resistors may still trigger faults. This varies by make and model, so check with an auto electrician who has the right diagnostic equipment for your vehicle.

    Option 4: go back to filament globes. If the vehicle came with filament globes, refitting the correct type is the simplest way to restore normal flashing and keep the lamp compliant.

    Keep it legal. Factory indicator lamps are approved under the Australian Design Rules with the type of globe they were designed for. Aftermarket LED replacement globes have generally not been approved for road use in Australia, and the NT Government’s vehicle standards page warns that non-complying lighting can see a vehicle defected or refused registration. Whatever you fit, the indicator must still show amber light and flash at the normal rate. Australia made a new standard for LED light sources (ADR 101/00) in July 2026, based on the UN rule that also covers approved LED replacement globes. Until a replacement globe is clearly marked as approved for your lamp and accepted by your state’s road authority, the safe choice is the globe type the lamp was designed for.

    Specs table

    Item Figure Notes
    Legal indicator flash rate 90 ± 30 flashes a minute (60 to 120) Set by the lighting installation rules; the rate may change when a lamp fails
    Common indicator globes PY21W or P21W (21 W); WY5W or W5W (5 W) Check the owner’s manual for your vehicle
    Current drawn by a 21 W globe about 1.75 A at 12 V 21 W ÷ 12 V
    Example 12V load resistor for a 21 W globe 8 Ω, sold to stand in for a 21 W globe One maker’s figure; draws about 1.5 A at 12 V (12 V ÷ 8 Ω)
    Load resistor surface temperature up to 170°C Maker’s figure; mount on metal only

    Globe types and resistor values vary by vehicle. Use the globe code from your owner’s manual and a resistor matched to the wattage of the globe it replaces.

    What you’ll need

    • PY21W amber indicator globe or P21W globe (as specified)
    • WY5W amber wedge globe (side repeaters, as specified)
    • LED flasher relay (vehicles with a plug-in flasher)
    • 12V LED load resistor 21W (one per LED globe)
    • self-tapping screws for mounting resistors to metal
    • crimp terminals and adhesive lined heat shrink
    • digital multimeter

    When to call an auto electrician

    • A new globe doesn’t fix the fast flashing, or both sides flash fast.
    • Your vehicle’s indicators are run by a body control module and need coding, or a lamp failure warning won’t clear.
    • The indicator lamps are sealed LED units. These normally can’t be repaired by replacing a globe.
    • You’ve fitted LED globes and want to be sure the vehicle stays roadworthy.
    • You can smell hot plastic or see melting near a load resistor. Switch off and stop using the indicators until it’s checked.

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

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    Related questions

    Q: Why do my indicators flash fast on one side only? A: A globe on that side has usually blown, or it isn’t getting a good earth. Check every indicator on that side with the hazards on.

    Q: Why do my indicators flash fast with LED globes? A: LEDs draw much less current than filament globes, so the flasher or body control module thinks a globe has blown. An LED flasher relay, load resistors or coding can fix it, but the lamp must stay compliant.

    Q: Is fast flashing illegal? A: Indicators must flash between 60 and 120 times a minute in normal use. Fast flashing is a warning that something has failed, so fix the cause rather than live with it.

    Q: Are LED globes legal in my indicators? A: Aftermarket LED replacement globes have generally not been ADR approved in Australia. Check with your state road authority before fitting them.

    Q: Do load resistors get hot? A: Yes, very. They’re designed to turn electricity into heat and can reach well over 100°C, so they must be mounted on metal, away from plastics and wiring.

    Sources

    1. UN Regulation No. 48 (installation of lighting and light-signalling devices), as published in the Official Journal of the EU – para 6.5.9: direction indicators flash 90 ± 30 times per minute; on failure of one lamp the others continue to flash, and the frequency may differ; para 6.5.8: tell-tale signals a malfunction by going out, staying on steady or changing frequency. https://eur-lex.europa.eu/eli/reg/2011/48(2)/oj/eng/pdf (checked October 2026)
    2. Department of Infrastructure, Vehicle Standard (Australian Design Rule – Vehicle Lighting) Amendment Instrument 2022 – ADR 13/00 installation requirements follow the UN Regulation 48 structure (clause 7.7 table, “6.5 Direction Indicator Lamp”); ADR 6/00 direction indicators reference UN Regulation No. 6. https://legislation.gov.au/F2023L00042/asmade/2023-01-19/text/original/epub/OEBPS/document_1/document_1.html (checked October 2026)
    3. Department of Infrastructure, Draft ADR 101/00 – Light Emitting Diode (LED) Light Sources (consultation draft, August 2025) – based on UN Regulation No. 128, including LED substitute light sources. https://www.infrastructure.gov.au/sites/default/files/documents/draft-adr-august-2025-101-00-vehicle-standard-australian-design-rule-101-00-light-emitting-diode-led-light-sources-2025_0.pdf (checked October 2026)
    4. Northern Territory Government, “Vehicle accessories” – aftermarket LED replacement globes marked off-road use only are not ADR compliant; vehicles with non-complying lighting may be defected or refused registration. https://nt.gov.au/driving/rego/vehicle-compliance-and-modification/vehicle-accessories (checked October 2026)
    5. Narva, “Why aren’t my indicators flashing correctly?” – load-sensitive flashers and LED globes; load resistor specification (12V, 21W, 8 Ω); operating temperatures up to 170°C; mount on heat-resistant metal. https://narva.com.au/narva-university/blogs/indicator-issues (checked October 2026)
    6. Narva, “Why aren’t aftermarket LED globes ADR approved?” – aftermarket LED replacement globes are not ADR approved; factory-fitted LEDs are. https://www.narva.com.au/blogs/blogs/2020/Dec/20/aftermarket-led-globes-adr-approval (checked October 2026)
    7. Wikipedia, “List of automotive light bulb types” – PY21W, P21W (21 W), WY5W, W5W (5 W). https://en.wikipedia.org/wiki/List_of_automotive_light_bulb_types (checked October 2026)
    8. Federal Register of Legislation, Vehicle Standard (Australian Design Rule 101/00 – Light Emitting Diode (LED) Light Sources) 2026, registered 9 July 2026. https://www.legislation.gov.au/F2026L00926/asmade/text (checked October 2026)