Volvo alternator warning lights
Warning lights should let you know when your car is in trouble. The alternator light, for example, should go on when you turn the key to the "on" position and go out once the car is started and the alternator is charging. If the alternator stops charging while you're driving, the alternator light should light to warn you of that fact.
Unfortunately, on many Volvos the alternator light does not come on when the alternator stops charging. The most common problem we see with Volvo alternators is worn-out brushes. The brushes are supposed to complete the field circuit and at the same time complete the amp light circuit. When they wear out and stop making contact, the alternator stops charging, but the amp light stays off. There is no way for you to know that the battery on your car is in the process of going dead.
There are subtle hints you as a driver can pick up if your alternator fails--if the alternator light does not come on when the ignition is turned on (before the start position) or if it does not flash momentarily when the engine is shut off, the amp light circuit is not working and most likely the alternator is not charging either. When you're driving down the freeway at night, these signs are of no use. The real solution involves two steps:
- Install a voltmeter so that you can see whether or not the battery is being charged.
- Look at it occasionally while you're driving.
Batteries don't go dead in a minute or two. When they do go dead, you may be in a spot where you can ill afford to be without any electrical accessories, including your running lights and your hazard flashers! A voltmeter is highly recommended.
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