When to change your alternator
“Your headlights will dim, other car electrics will start to malfunction and you’ll have to jump-start your car to get it started”
An alternator’s bearings cause most failures (it starts to get noisy when the engine is running), but the drive belt can snap or become loose.
When the alternator isn’t working your battery isn’t being charged (you should see a red warning light or other message on your dashboard) and it’ll go flat quickly - your headlights will dim, other car electrics will start to malfunction and you’ll have to jump-start your car to get it started. But this won’t work for long before the battery fails completely.
If the alternator glitch has been caused by drivebelt failure, you should be able to get away with tightening or replacing the belt, but if the alternator is faulty it should be replaced without delay.
All cars are slightly different, so if it is time to change your alternator, use our before you begin checklist, and find your car for specific instructions.