Quick answer
If the dash lights go dim or out when you turn the key, or you hear rapid clicking, the battery (or its connections) is the usual cause. If the lights stay bright but you get one click or nothing, the starter motor, its solenoid or its wiring is more likely. A jump start is a good test: if the car starts straight away on a jump, look at the battery and charging system first.
Is this a DIY job?
- Difficulty: Medium (the checks are easy; replacing a starter is usually Pro)
- Time: 15 to 30 minutes to diagnose
- Tools: digital multimeter, jumper leads or a jump pack, safety glasses, gloves, terminal brush
- Skills: reading a multimeter, working safely around a battery
Most people can do these checks in the driveway. Swapping a battery is an easy DIY job. Replacing a starter motor means working under the car or deep in the engine bay, so most owners leave that to an auto electrician.
Step by step
- Make it safe. Park on level ground, handbrake on. Automatic in Park (try Neutral too). Manual in neutral with the clutch pressed fully down when you try to start.
- Rule out the simple things. Check the key or remote battery, and that the immobiliser or security light isn’t flashing. A flashing key symbol points to the immobiliser, not the battery or starter.
- Listen when you turn the key (or press Start). Note exactly what you hear: – Fast clicking or chattering: usually a low battery or a poor battery connection. – One solid click, then nothing: often the starter solenoid, the starter motor or the heavy cable to it. – Slow, laboured cranking: a weak battery or a high-resistance connection; sometimes a worn starter. – Nothing at all, and the dash is dead: flat battery, or a terminal that’s loose or corroded. – Grinding: the starter gear isn’t meshing properly. Stop trying and get it checked.
- Do the headlight test. Switch the headlights on, then try to start. If the lights dim heavily or go out, the battery can’t supply enough current. If they stay bright and nothing happens, the power isn’t getting through the starter circuit.
- Check the battery terminals. Look for white or green corrosion, loose clamps or a cracked terminal. Wiggle each clamp by hand. If one moves, that alone can stop the car starting.
- Measure the battery voltage. With everything off, set the multimeter to DC volts and put the red probe on positive (+) and black on negative (−). Compare with the table below. If you’ve just driven or charged it, the reading will look better than it is. For a true reading, let it rest for several hours, ideally overnight (one battery maker suggests 24 hours without driving).
- Measure while cranking. Have a helper crank the engine for a few seconds while you watch the meter. A big drop (see table) points to a weak battery. If the voltage barely moves and the starter does nothing, the problem is between the battery and the starter.
- Try a jump start. Follow your owner’s manual for jump points (some cars have remote jump posts under the bonnet). If it starts normally on a jump, the battery is flat or failing. Then find out why: an old battery, a charging fault or something draining it overnight.
- If a jump makes no difference, and the battery reads well, suspect the starter circuit: the starter motor, solenoid, starter relay, ignition switch, or the neutral/clutch safety switch. These need a proper circuit test.
Specs table
Symptoms and the usual cause
| What happens when you turn the key | Dash lights | Most likely |
|---|---|---|
| Rapid clicking | Dim or flicker | Low battery or poor terminal connection |
| Single click, no crank | Stay bright | Starter solenoid/motor or its cable |
| Slow crank, then starts (or not) | Dim during crank | Weak battery, corroded cable or earth |
| Nothing, no dash lights | Off | Flat battery or disconnected terminal |
| Nothing, dash lights normal | Bright | Starter circuit, relay, ignition or safety switch, immobiliser |
| Grinding noise | Normal | Starter drive or flywheel ring gear |
Battery voltage guide (12V lead-acid, engine off, rested)
| Reading | Approximate state |
|---|---|
| About 12.6 V or more | Fully charged (battery makers often quote 12.7 to 12.8 V) |
| About 12.4 V or less | Partly discharged; charge it before judging |
| About 12.0 V or less | Flat (fully discharged) or failing |
During cranking, a common workshop guide is that a healthy, charged battery shouldn’t drop much below about 9.5 V. Much lower than that suggests a weak battery or a bad connection. Lithium starting batteries and some AGM batteries read a little differently; check the battery maker’s figures.
What you’ll need
- digital multimeter
- jumper leads heavy duty or portable jump starter
- battery terminal brush
- battery terminal protector spray
- smart battery charger
- If confirmed: car battery or starter motor
When to call an auto electrician
- The battery tests good but the car still won’t crank.
- You hear grinding, or the starter keeps running after you let go of the key. If the starter won’t stop, switch off the ignition and, if it’s safe to do so, disconnect the battery negative terminal.
- There’s a burning smell, smoke or a hot cable near the starter.
- The car has a push-button start, keyless entry or an immobiliser warning you can’t clear.
- It’s a hybrid or EV. Many hybrids don’t have a conventional starter motor, and their high-voltage systems are professional-only. Never touch orange cables.
- A new battery keeps going flat. That usually means a charging fault or a drain that needs proper testing.
Need an auto electrician? Find local auto electricians and mobile services in your city.
Related questions
Q: Can a bad starter drain my battery? A: Yes, in some cases. A starter that drags or draws too much current can flatten a battery during repeated start attempts, and a faulty solenoid can occasionally stay engaged. A current-draw test will show it.
Q: Why does my car start fine with a jump but not on its own? A: The battery is flat or no longer holds charge, or a terminal is loose. Once it’s running, have the battery and the charging system tested so you know whether to replace the battery or fix the alternator. (see How do I know if my alternator needs replacing?)
Q: Does tapping the starter motor fix it? A: Sometimes a tap gets a worn starter to work once, but it’s not a repair. If that’s the only way it starts, the starter or solenoid needs replacing soon.
Q: How long should a car battery last in Australia? A: It varies with climate, driving habits and battery type. Heat is hard on batteries, so regular testing matters more than the age on the label.
Q: My car clicks but the battery is new. What now? A: Check the terminals are tight and clean, then check the earth strap and the main cable to the starter. If those are fine, the starter or solenoid is the next suspect.
Sources
- RACV, “What do the car dashboard symbols and warning lights mean” – battery/charging light advice. https://www.racv.com.au/royalauto/transport/cars/what-do-the-car-dashboard-symbols-mean-and-warning-lights.html (checked October 2026)
- RACV, “Car battery replacement” – battery management and registration note. https://racv.com.au/on-the-road/roadside-assistance/car-battery-replacement.html (checked October 2026)
- Century Batteries, “How to test a lead-acid battery” – 12.7 to 12.8 V fully charged; recharge at 12.5 V or below; 12.0 V fully discharged; vehicle not driven for 24 hours before testing. https://www.centurybatteries.com.au/battery-hub/expert-advice/how-to-test-a-lead-acid-battery (checked October 2026)
- VARTA, “Testing the battery – step by step” – recharge a conventional battery as soon as possible if it reads below 12.4 V; a voltage reading shows state of charge, not battery health. https://www.varta-automotive.com/en/knowledge/articles/article-details/testing-the-battery—step-by-step (checked October 2026)
- RACV, “Car battery guide” – 12.6 V fully charged (rested). https://www.racv.com.au/royalauto/transport/cars/car-battery-guide-how-to-know-if-it-needs-replacing.html (checked October 2026)
- Brake & Front End, “Diagnostic solutions: testing automotive batteries and starters” – 9.5 V minimum cranking voltage threshold in a load test (workshop rule of thumb, not a formal standard); test starters only with a fully charged battery. https://www.brakeandfrontend.com/diagnostic-solutions-testing-automotive-batteries-and-starters/ (checked October 2026)