Hi, I have a 2003 Pontiac Grand am 2.2 liter. Anyway, someone broke into the car at night and tried to steal the battery and cut the cables. They apparently did not have any sort of wrench to unbolt the bolted down battery so they were unsuccessful but they arced the cables causing some sort of electrical damage.
Right now the battery light will not turn off on the dash and the battery is not charging. So far I have replaced the cables and installed a new alternator. I just pulled the new alternator and had it tested and it passed all tests. The battery was tested as well and is okay.
Does anyone have any idea what the problem could be? I am not sure how to proceed next. Thanks.
Unfortunately the butchery that was done in an attempt to steal your battery may have damaged the vehicle's electronics. On many cars there is no longer a separate voltage regulator or one built into the alternator, output is controlled by the ECU. In that situation if the ECU is damaged the battery won't charge even if the alternator is good.
I had a feeling that, that would be the case. I have a friend that is a GM certified mechanic but didn't want to bother him with it but I guess I am going to have to at this point. Thanks for your response.
If your friend is a GM mechanic he probably has a Tech2 which would be the dealer scan tool for that car. Possibly he'll be able to tell with that if the ECU was damaged. (I'm not sure if you have that setup but it's common and a quick check of the Rockauto database does not show a voltage regulator available for that car.)
Okay thanks, I will get ahold of him tonight and see what he says.
Maybe recheck that GENerator fuse in your engine compartment fuse box
I just checked all of the fuses in the engine compartment box and they look okay.