[Weezie]

I have a 2004 Impala. If you use alternate power source, the gages start jumping up and down, there is a thumping beating sound that comes through the speakers & then the battery is dead. Takes a long time to restart when jumping the battery. Also have had issues with high beam lights - all the car lights go out when the high beams are put on. Turning the car off and restarting immediately doesn't resolve the issue. It has to be turned off for quite some time for the regular beam lights to work again.

 

[capricewiz]

Its not an everyday thing where the alternators go back, its usually the battery. But it happens. I would still check the battery first, then if you have a multimeter, check the voltage at the battery while the car is running and you have all your lights on and wipers on, and you should have over 13volts at the battery. If you don't, you'll need an alternator.