Tx9h6e4cuda

This morning i started up my 2001 Cherokee and everything worked fine. I went to a friends house and left it for three hours. When i started it and the check gauges light came on. I looked at the volt gauge and it was buried at 9. Well i stopped and restarted it and it went to 13.8 and after a block it went to 9 again andthe check gauges light came on. I let the truck sit and it seemed to work ok. Well i went to autozone and Gomer behind the counter tested my battery and alternator and told me "your voltage regulator is bad time for a new alternator". I left abd removed the alternator and found the case was cracked really bad. Well i brought it to checkers and they tested the alternator is testing good. I went ahead and got a new one because maybe the voltage regulater is bad inside and might be going bad. So if it isnt the alternator what could it be?

Turbo X_J

Voltage regulator is in the PCM. Sounds like a connection/ground issue, if not PCM could be on it's way out.

tjwalker

Most likely the alternator. Install the new one you purchased.

Dan_Man

check your alt fuse it should be fuse 8 in your pdc

tjwalker

I don't think the alternator is fused for an 01 through the power distribution center.

http://www.lunghd.com/Tech_Articles/...tification.htm

VTJeep

Is your belt tight?

Tx9h6e4cuda

Well i replaced the alternator and tightened the belt (im ordering a new one tomorrow) and it seems to run fine but the alternator gauge is running a small line under the 14 on the gauge. I remember before it ran at 14 exactly in the middle of the gauge.It makes me wonder so im gonna pull a battery i know is 100% and try that otherwise im driving it just the way it is. If tye voltage regulator goes out then i will know where to go next. Its really dumb that they put the voltage regulator in the computer so i have to pay for the piece of crap to get reflashed. I would love to meet the guy that invented that in a dark alley......i know i would make it out.

macgyver35

Yep, a failing PCM can cause this. The old one in mine did EXACTLY what you described yours (OP) doing. Fortunately, I had another PCM that was known good that I could swap with temporarily. When swapped the issue went away, so I ordered a rebuilt PCM on ebay for a couple hundred. No problems since.

tjwalker

Always best to verify your charging system. Takes 2 minutes with a simple multimeter. Buy one if you don't have one.....you can get one for as low as $10. A pretty darn nice one for $25. It is a critical tool for anyone working on their XJ.

Put the meter on DC volts range and put one lead on each of the battery cables with the engine running.

With a properly charged battery and a solid charging system, you should see about 13.5 to 14.0 volts on that meter.