Q: Q: Battery light on while driving but then goes off?

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had mechanic look at it with diagnostics said no problem with alternator battery light comes on but goes off . said something about thermostat but no sure as i didn't speak to him myself. would this make my battery light come on. kindregards mark

My car has 13000 miles.
My car has a manual transmission.

This may be a sign of a failing alternator. As you may know, the alternator is responsible for charging the battery while the engine runs by generating amperage and recharging the battery while the engine turns the alternator. 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. In either case, I would recommend having an expert from YourMechanic come to your location to diagnose your alternator.

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