Thread: 2008 Grand Prix

I am working on a 2008 Grand Prix that was in a front end collision, I rebuilt it and am now having a problem with the charging system cooking the battery.

It was steaming. I assume it is overcharging the battery.

Any ideas on what or where to look into?

I did repair a few wires that go to the throttle body, I wonder if there are others that are damaged?

Any help will be greatly appreciated.

-Jay

Originally Posted by SyntheticShield

One of two things comes to mind. Either 1.) the Output regulator in the alternator is fried or 2.) the reference voltage used to determine output voltage is way off. If number #2 were the case, however, you would notice all kinds of crazy issues as the PCM and other electronics would be freaking out with the overvoltage. So my guess at this point would be that the regulator in the alternator is toast.

Any way to test the alternator?

Could it be acut wire somewhere?

Originally Posted by SyntheticShield

You can take the alternator to Autozone and they will test it for free. You can take it off the car or you can drive it to them and they have a portable testing unit that will test out the entire charging system.

I put my multimeter on the battery when car off and got 11.8 volts

then I started it and got 14.6 volts at the battery and alternator.

Seems like it should be fine right?

Why else would the battery have steam coming out of it?

The battery does go dead overnight.