I have an electrical problem with my 96 Jeep Grand Cherokee. The alternator whines and the battery gauge drops to zero. I put a new battery in and a new alternator and it didn't fix the problem. any advice?
You need to inspect the following:
- Serpentine belt (actually, change it if you haven't done so already)
- Tensioner pulley - While the tensioner may appear as though it's good, it may not be giving the belt enough tension so it has traction on the accessories.
One of the two is going to be your issue. There is the outside chance you received a bad alternator.
Are you sure it's the alternator that's whining?
Check your connections the Field plug on the alternator and the alternator to battery cable. There should never be zero volts coming out of the alternator. It will always be battery voltage or charging voltage. Test voltage at the battery. then at the alternator if the alternator show charging voltage there may be a blown fusible link.
If the volt meter on your instrument cluster shows zero the cluster/gauge may be bad. Or there is a problem with the serial data line between the cluster and PCM. Or there is a problem with how the PCM is receiving input voltage, probably from the ASD relay or similar.