Battery light on dash came on...had battery, starter and alternator tested found all was good except low output (about 12 volts) on the alternator.

Alternator is pretty old and recently got swampped on a mudding trip so gonna replace it but wondering if there is any good easy/bolt on upgrades I can do?

Side note check engine light P1391 came on randomly shortly after battery light, could this be related?

 

Raining tomorrow gonna replace Sunday so looking for help quick, help me out.

 

google

 

Did that...I live in Google's backyard and use it well, thanks. If you read my post I ask for bolt on upgrades. All I found was non bolt on which I haven't had good luck with lately so looking for bolt on. Everything I found was either for older XJs or old post so hoping there was a newer solution.

Also wanted opinions on difficulty in specific to the '97 as that was more answered about older XJs...

Then there's the CEL question...

Thanks for pointing out the obvious though and I'm sure others will be more helpful.

 

I don't see how the code can be related only way to check is fix the alternator and see of it goes out .

But unless you willing to do a really small about of grinding your sol I got a 98 and did the 120 amp upgrade really simple and only takes maybe half an hour more

 

3mos ago bought 220a alt from ebay "alterstart"

lil bit of grinding with a dremel, otherwise bolt in, no pulley swap

 

Low voltage can wreak havoc on the OBD and cause all sorts of DTCs to pop up. 12 volts is considered low "running" voltage. on my brief search for P1391 it showed that it was a cam/crank sensor fault which relies heavily on the ECM's ability to read the proper voltage. If it were me I would certainly start by replacing the alternator, clearing all DTCs (which will be done when you disconnect the battery for the duration of the job), and then test drive the vehicle to see if the fault returns. However with all that said Jeeps are known to have those sensors fail occasionally so don't be too disheartened should the fault return.

 

That means they weren't "all good". Low voltage output (less than 13.5 volts) is an indicator of a bad alternator. 97's came with a 90 amp alternator stock but 2000-01's had a 120 amp alternator that should bolt right in.

 

Thanks for the info guys. I'd like to stay away from even grinding but seems like that isn't an option.

SMH, knew someone would say something and I should not have shortcut'd & just wrote it all out..."battery good, starter good but alternator voltage low". I was on a cell phone so tried to avoid writing them all out again after saying I had them all tested.

Can anyone confirm 2000-2001 alternator is 120 amps and is bolt on?

 

I think you can get the 120a alternator for a Grand Cherokee.

http://www.quadratec.com/products/55100_0504.htm

Grinding the bracket might not be a HUGE deal.
Seems like Chrysler has some direct fit 130a version, as well.
https://www.cherokeeforum.com/f67/ch...pgrade-137921/

http://www.autozone.com/autozone/par...mString=search

130m but larger
http://www.autozone.com/autozone/par...vice=262371439

 

Didn't notice before but there does appear to be a 136A alternator available for the Cherokee (put in my year) that's around $40-$50 more than the 90A. I will assume the 136A will fit the same as the 90A with no grinding or modification needed.

 

136A:

http://www.oreillyauto.com/site/c/de...1468&ppt=C0330

http://www.autozone.com/autozone/par...065_23521_2994_

 

I saw this on oreilly's too and was thinking the same thing, hopefully someone knows if it will bolt on without modifications.

 

In this thread https://www.cherokeeforum.com/f67/ch...pgrade-137921/ that BimmerJeeper linked I saw this as well:

But haven't been able to find this part or any information on it...

 

Yeah I'm willing to pay the extra money but would be nice to get some verification on if it is a direct bolt on meaning NO grinding, haha, before I buy it.

Almost got my old alternator out minus one of the "field terminal nuts" (two 7mm nuts on back of alternator) won't come off. Soon as I get it off I'll need to make a decision on a replacement.