I have a 1987 cherokee and have a bad voltage regulator. There are 3 different versions that I can purchase. I have a photo of each. And can not find either. Can someone please tell me where it would be located so I can get the correct one and replace it. Before I pull what little hair I have left out.

 

on those its inside the alternator

 

^^This^^
It's an internal regulator.

 

Yep. 91 on HO w/PCM, in the PCM. 87-90 Renix w/ECU, in the alt.

 

I have replaced the alternator twice. When I test it on the vehicle it reads it has a bad voltage regulator. When the alternator is tested off the vehicle and on the bench it test good. Because of those results I replaced the ECU last weekend and it still reads bad voltage regulator. Any suggestions on what to try next?

 

Yep. Realize that the ECU has NOTHING to do with the charging system.

Click on the link below in my signature and do Tips 1 through 5.

 

It's always a good idea to listen to Cruiser. I'm curious Pete, is ther a crucial yellow "trigger wire" that goes through that "notorious" C-101 connector? (#2, &,#27 in your tips, IIRC)

 

Thanks guys. Cruiser, what is that link? I would

 

I would like to try what you are suggesting but couldn't find your link.

 

It's the PINK link !...lots of good info there from Cruiser !!

 

It's in my signature. Here, in case you're on an App.

https://docs.google.com/file/d/0Bz4d...aEE/edit?pli=1

 

Thanks, I do use an app on my phone.

 

Cool. Now get to work....

LOL.

 

What I don't understand is "it READS it has a bad voltage regulator"..... WHAT reads that? '87s don't have OBD or any system that reads anything.

 

its the stupid dummy type new school VAT tester, or now called a electrical system analyzer..