zombiehunter99

Okay im stumped I put a new battery cause me old one took a crap. But my volt meter sometimes drops to 12v then back to 14v. So I tested my charging system at work (AutoZone) and my charging system checks good with no accessorys on. But when I turned my lights, wipers, blower, etc on at idle my voltage regulator failed and our machine is saying voltage is 12.59v with accessorys on. But if I rev my engine to about 1,500 rpms my voltage is at 14.02v and everything passes with accessorys on and engine at 1,500 rpms. What? My coworkers saying my alternator is on its way out. Cause rarely the Voltage regulator goes on the Cherokee cause its in the pcm. Some are saying check my wires on my battery and alternator for loose or broken or cracked connectors.

Just what to know what you guys think. I love my jeep but if its my pcm idk what to do $277 part.but I can see my alternator going before the pcm does......

Dan91

Definitely sounds like the alt is on it's way out. Most often you can just get away with replacing the brushes on it. If not just get a new one and swap it out. 12.5ish volts basically means the alt is maxed out and the accessories are running on battery reserve. Voltage output should stay at around 14v with accessories on at idle.

zombiehunter99

Thats what I was thinking alternator going out. Sometimes it want to die on me but if I step on the gas it straightens out. I went to my local jy today and the olny two Cherokees in there was hit on the passenger side right where the alternator is. But one was not hit that bad I too the alternator out but the connector was the bost style my jeep is the connector style, so I looked and the jeep was a 98. Mines a 99. But I hear an alternator from a grand Cherokee would work but through out the years either the connector or alternator bracket was different. I may just buy one from work for 100 but did the Cherokees have an option with a higher amp alternator and will be a direct bolt on for my jeep if so where

investinwaffles

Do you have an angle grinder? If not buy one, and buy a Dodge Durango or Jeep WJ alternator (both 136 amps).

There are like 80 threads about the swap, so search till you find a tutorial that you like and get to it! Took me about an hour to get the Durango alternator dropped in place, including grinding the bracket and block.