i just bought my first jeep. its a 1996 jeep grand cherokee limited with the infinity gold sound system. it has sat for about a year and has 230,000 miles on it but it was running good but not grate. none of the interier lights work witch dont bother me. but all of the speakers where blown and no cd player. the first real problem is that the battery keeps dieing. and when driveing the volts were reading downaround 13 witch is not good. but my maine gole was to put a sound systum in it. i got a aftermarket cd player and speakers form walmart of course. i put them in and had to bypass the amp. now the sound is better then before witch is grate. now the battery is new and is still dead every time i try to crank it, and the check battary comes on and the volts read past 19 when driveing, and 16 at an idle. it fryed the battery. so i replace the alternator and put another new battery in it and it still reads 16.3 at an idle. is it caused by me bypassing the amp??????? PLEASE HELP!!

Sounds like a short is causing a constant drain on the battery.

what would cause that. and is there a way to find out where it is. i know the neg. of my left rear door speaker would not work and i grounded it to the door, would that do it or is the neg that not working be it

If you have a test light, take your positive cable off and connect your ground on the test light to the terminal and the other to the battery if it lights up you have a short.
next take out the fuses one by one to see where the short is. that should narrow it down.

It sounds like the voltage regulator on the alternator has been fried. It regulates the amperage output/volts the alternator charges at.

It sounds like the voltage regulator on the alternator has been fried. It regulates the amperage output/volts the alternator charges at>>>>>>>>>>

I think he replaced the alternator.

I'd suggest keeping your battery disconnected when not in use so it doesn't burn out.

The voltage regulator is in the PCM, not the alternator.

so get this. all of the tests i did came back to be every sensor in the jeep is bad. what the hell is going on. well before i bypassed the factory radio and amp everything was fine but the battery dieing. now the radio works but cant drive it without it going all crazy. so what do i do. i put the factory radio and amp back in and now this beast comes alive. now with so much more power the belt cant handell it and snaps off. new belt and no cd player and shes alive and well. fu#$ infinity gold, i think it sucks.

Back to basics all..................
Sounds like 2 issues...............
Work on the battery issue first!

Disconnect the battery over night. Dead in the morning its a bad battery
If the battery starts the car in the morning, the next night take all the 30 amp fuses out. Then the 20 amp, then the 15 amp and so one............
One morning your going to have a hand full of fuses out BUT the jeep will start.
For example, you have taken out 4 5 amp fuses, and the Jeep starts. Put half (2) of them back in. Does it start the next morning?
Very quickly you will ID the circuit with the drain. FIX THAT CIRCUIT.

Alternator issue
Historically the PCM voltage regular is pretty crappy about doing the job, but they also dont go bad very often. Get the other fixed and see what the REAL voltage is at the battery and at the alternator with the Jeep running. The dash gauge is not exactly calibrated. Regardless Im betting with the battery fixed, the alternator will be fine. If not we'll help with deciding whether the alternator or regulator is bad. Regulator = New PCM

Ron

i put the factory radio and amp back in and now this beast comes alive. now with so much more power the belt cant handell it and snaps off. new belt and no cd player and shes alive and well.>>>>>>>

I'm hardly a mechanic and I don't pretend to play one on TV but this is kind of bizzare?

Have you tried it without any radio or amp installed at all?

I run the stock Infinity system and it seemsto me that my battery runs a little lower then I'm comfortable with if I'm doing work on my Jeep and have the radio/cd player running for a while.

I had an old El Camino that developed electrical problems that started to interfere with my sound system, every time I hit the brakes I'd hear a bass thump in the speakers. I ended up having to just leave the battery disconnected whenever it was going to sit for more then about 30 minutes. Eventually found a short in the starter was causing my battery to drain.

Since you first stated that none of your interior lights worked I'd start there looking for the short. Possibly a bad dimmer switch or door jamb switch shorting to ground. JMO

One thing I have seen is the brake light switch that is under the dash mounted near the brake pedal. Even if the brake lights are not on, the switch is in the open mode and the battery drains. The switch is s6075 at Oreilly for 12.00. I have seen a lot of these cause this. Hope this helps.

Ghosts in the machine! No fun...