Roler

paper document!! Like finding that old guitar!
I'd be happy with any info on where or how to test, cheers!

cruiser54

I looked at it earlier. 92 manual. Won't work for your 97. Crud.

djgrayxj

Note from DJ
I DON’T KNOW if this posting will help or not
Title of posting By awg on 3-2-20 is Powertrain Diagnostic Procedures Manual for Jeeps

LINK TO POSTING.
https://www.cherokeeforum.com/f2/pow...manual-256139/

Before I forget, one of the guys on our Aussie forum found this free download of the "Powertrain Diagnostic Procedures Manual"

It can be used in conjunction with the FSM, but has advanced fault finding flowcharts.

At ~300 pages, it appears to be what in-house techs would have used.

The free download is for OBD1 vehicles, but still quite applicable to OBD2

Power Diagnostic Procedure for 1993 to 1995 Jeeps
Open from Posting only with this link
https://drive.google.com/file/d/0B0n...JobGVvbjg/view

Or 0pen form Google with this link
https://drive.google.com/file/d/0B0n...Rzar0WUAShqX-A

Roler

Thanks DJ
I'm downloading and will have a look what I can find to see if it can be apllied to my year.

Roler

So found this, not sure if the screenshot is helpfull but thought for completeness.

No word on the voltage output at idle but basically saying that: (if voltage drop test are within spec)if the voltage between idle and 1600rpm is great than 1.0 , to repair or replace the generator. That's it.

Hope they don't jump to replacements too easy: reading up on battery sensor voltage for instance it says that if its out of wack (throwing a code though) and the code persist after deleting the code, to replace the PCM 😳. Sounds a bit drastic. But that's no my problem!

So when the weather clears up, I'll be taking the alt out and see what I can find and clean up.

Roler

Read about one more suggestion on another forum.
Sometimes the alt pulleys aren't entirely correct size, esp if they have been reman-ed. If its larger, the belt would spin it at less rpm's and it would make sense it doesn't charge at idle as it should (although it would be weird to first have worked and not anymore now)
Anyway, the weather cleares, I had some time and had my OEM alt still here so compared with the one in there atm: pulley diameter difference about 3 mm. Curious what the influence of the relative "smaller" pulley would be on the voltage output at idle, took the alt out again (getting pretty handy with it by now) swapped the pulleys, put in back in. Alas, it made no difference. Haven't got a super small pulley to try but the theory made sense!

Slowly...but surely... I am dragging myself towards admitting to have to fork out a new alternator. But not because of lack of trying, ha!

Outlaw Star

It's more of "This place is like the mafia, you can leave but you're never out."

awg

I have tried 3 used ones in a row in my spare '96 and the "gen light" still comes on, even after I put new brushes in one

Might have to risk try one of them in my DD to see if its the PCM or wiring

sure dang tired of swapping them over, but I can do it in about 15min now

Roler

Hey Outlaw around too!

Funny you mention the mafia; Cruiser's first response to my return made me think of the scene from The Godfather below (if familiar with it) where he replies to someone asking a favour, who has never invited him for like a drink or dinner LOL. Of course he grants the favour, leaving the person forever in his debt..

Ps: I could never leave 'La Famiglia'. Even if I no longer owned the XJ..

Roler

Yep at least thats a little plus with the RHD's: the location of the alternator. Sure helps 'cause I aint getting younger lol

Roler

Where on the alternator could I check for the signal it is getting from the ECU?
edit: would that be stud nr 3 in my pic in post nr 20?

Roler

Could I use a Bosch type alternator instead of the Denso?
Or does that type (Bosch) have an internal voltage regulator?

Jim Malcolm

Maybe this post will be helpful to answer your previous question...

https://www.cherokeeforum.com/f67/al...2/#post2459583

Roler

Yeah that thread doesn't really get there. But thanks for the link. Done a lot of searching but now..

Jim Malcolm

One terminal is connected to the ASD Relay, the other grounded by the PCM. I'm not 100% certain whether the ECM output is on-off or proportional, but you can test the alternator by just grounding it. It"s extremely unlikely that the PCM would work at high RPM but not low RPM, while that is very much the symptom of a failing alternator.

edit: Many other options out there, including OEM parts, but ...

https://www.summitracing.com/parts/meh-91102rc