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Q: Alternator and battery - 2002 Chevrolet Avalanche

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My battery light comes on and off when I first start my car, the radio turned off but everything is working again and my volt meter is between 12 and 14. I don't know what's causing this problem. My alternator registers as good and so does my battery.

My car has 171589 miles.
My car has an automatic transmission.

A: Hello. This may be a sign of a failing volt...

Hello. This may be a sign of a failing voltage regulator or potentially a faulty connection somewhere in the charging system causing the light to come on. The voltage regulator is a unit that regulates the charging of the battery by the alternator. Often times, this will result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. In other cases, it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. If you would like to have this taken care of, I would recommend having a certified professional from YourMechanic come to your car's location to diagnose the battery light and advise on repairs.

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