Pontiac Repair Questions? Ask a Mechanic for Answers ASAP
Welcome to Justanswer ! my name is XXXXX XXXXX i will do my best to assist you with this problem
so your battery will go dead ?
how low will the charge read with those things on ?
Well I hope your answers get better as we go. NO my battery did not go dead. They just tested the battery and alternator for a minute to check that they were charging properly with the a/c, lights on.
The gauge started going down while he was testing and moved back to normal when I would shut the a/c off. Does this help you.
I did not want the gauge to go into the 'danger' area which would take longer than a minute or two.
as you can see it was not an answer I gave you but a few questions to gain more insight on your issue
how long have you owned the car ?
will it only do this at idle ?
while driving with the A/C on or the rear defroster on ?
Okay...I have owned the car for 13 years and have had no problems like this in the past and I keep everything!
The gauge goes down while setting at a stop sign but will continue to go down slower while I am driving, but still goes down.
I ONLY have the problem when I am trying to use the a/c or defroster.
ok thank you for the information
the A/C and the defroster are the biggest draw on this charging system when on
when the engine is running the alternator should be able to keep up with any electrical draws or demands asked of the electrical system at all times
since it will do this when driving also we can rule out a basic low engine idle so to say that will not increase the idle at a stop when the engine is on and those things are turned on
driving at speed and it does this would narrow this problem down to an internal alternator issue possible battery cable connections
that alternator either can now physically keep up with the demands due to internally failing OR the alternator is not being told to full charge when you demand more when turning those things on
the PCM = engine computer monitors the demands and will tell the alternator how much to charge
a shop needs to get this to act up and unplug the alternator and connect the alternator test tool and see if the PCM is telling it to charge if the PCM is telling it to charge the alternator would need to be changed
if it is not telling it to charge then the PCM would more than likely be bad and would need to be replaced
If I understand what you have written, it is either a computer malfunction, meaning the PCM is not giving the instructions to the alternator, or if it is, then the alternator is not functioning properly.
Is that what you are trying to tell me? If so, this gives me something to give to my shop owner when taking it to him on my next visit.
yes that is what I am telling you