DFlintstone

Apples and oranges. Mud, I believe your (internally regulated), alternator output meets a wire to the battery on the starter relay there near the battery. (there is a diagram in my signature). Coach's (externally regulated) might meet in a PDC?.

DFlintstone

jmrec100, Without really knowing I'm thinking that is not so easy. (it's a PCM Btw, ECU is 90 and earlier). It might be the PCM does not actually provide field current, but instead a signal to the (post 90) alternator, telling something internal how much field current to provide.

If your Alt and connections are now OK, maybe a replacement Powertrain Control Module might be your best bet. Might be relatively affordable at pick n' pull.

OldMud

Thank you for that link. Someone had extended the wire for the fuse to rest behind the headlight (who does that) and the wire had shorted out. Replace the wire and the fuse and she's back!

DFlintstone

HEY! We got a Bingo! . Well done, Happy trails! (I'm not aware of any fuse between my alt. and where it meets the wire from the battery at the starter relay)

OldMud

Yeah I believe that's where my problem started. I've never heard of the fuse. The wiring looks like it was installed aftermarket. There are a couple things I'm still finding. (Aftermarket voltage Regulator bolted to fender)

DFlintstone

Well, welcome Alberta Mud. Sounds like a new thread, instead of making Coache's a mess!

jmrec100

PCM. Got it. It's the 'brains'. I did get a rebuilt PCM. Issues gone. But I sure as heck check my grounds every month or two.
I was asking about how to go external voltage regulator. But didn't think can. I'd rather fry alternator than the PCM again.
I was thinking of just buying another PCM. But would have to have all the same options as I have on mine. I went and had to drop an engine/trans in my beater DD Chevy Cavalier. Had a heck of a time getting the right computer for it. Eventually, ordered one and had it programmed for my specific model. A pain in the ..... Is it the same for Jeeps? I imagine it is.