What does it mean when the key makes a clicking sound but the engine won't start?
3 Answers
The reason why the key makes a clicking sound but the engine won't start is due to a malfunction in the starter. Common faults include: the starter not turning or moving slowly, loose terminal connections, severe wear of the brushes, short circuits or open circuits in the field coil or armature coil, dirty commutator, or protruding mica sheets causing poor contact between the brushes and the commutator. The solution is: use a household multimeter to measure whether the car battery voltage reaches 12V or above. If the measured voltage is less than 10V, the vehicle cannot be started, and the battery must be charged or jump-started using another vehicle's battery. If the battery is normal, use the multimeter to check if there is power at the starter's power supply terminal. If there is no power, it indicates a power supply issue in the starting system, and it is necessary to check for loose, broken, or aged starter wiring. After repairing, try turning the key to start the engine again.
I've been driving for over 30 years, and this clicking sound is quite common. It's mostly caused by a weak battery. When you turn the key, you only hear the relay clicking, and the starter can't even budge. Quickly check if the dashboard lights are unusually dim, or press the horn to see if it sounds weak. If the battery is dead, you can jump-start the car to get by. However, it could also be a faulty starter solenoid. I once had a case where the solenoid contacts were burnt, and even the gears got stuck. Loose electrical connections can also cause this—a friend’s car had oxidized wiring harness connectors that blocked the current. Remember, never stubbornly keep trying to start the car; if it doesn’t respond after three to five attempts, stop immediately to avoid burning out the starter motor. Cold weather makes this issue more likely, so it’s best to test the battery capacity before winter every year for older cars.
In my auto repair shop, we encounter this issue every day. The clicking sound indicates the starter relay is working, but the starter motor isn't turning - 90% of the time it's due to insufficient battery voltage. First, use a multimeter to test the battery; if it's below 11 volts, that's likely the culprit. If the battery is fine, then check for loose connections at the starter terminals and whether the solenoid switch contacts are burnt out. Last week, a customer brought in an SUV - after lengthy troubleshooting, we found the starter fuse had blown; replacing it with a 15A fuse fixed the problem. Another case was caused by an anti-theft system malfunction locking the electrical signal. Reminder: pay special attention to battery terminals during rainy seasons - those green corrosion crystals can dramatically increase contact resistance. Don't attempt to dismantle the relay box yourself - short circuits can create bigger headaches. We recommend a comprehensive electrical system check every two years.
