thorguy57

Do you have a repair manual? Go to your wiring diagram for the charging system and look at the connections for the alternator. You have one wire that goes to your battery to charge it, another that goes to your ECM for your voltage regulator and a third (Dark Green, Red and then turns to Dark Green/Orange) Which goes to your ECM and also your injectors. My guess is underneath that black piece you have a bad connection on the Dark green/red wire causing you to lose power to your ECM and injectors. PPull the black piece off and clean up all the connections real good. Then if you still have problems take your meter and ohm between then Dark Green/Red wire and also the Dark Green/Orange wire at the ECM or injector and have someone move the wires while you read the meter. If you get an open then you have a broken wire somewhere.

hotrod6657

I have a basic Haynes manual, but I'm having trouble finding it right now.

I don't have a garage to work on it right now but tomorrow I'm going to try and use a friend's garage and I'll see if I can make some progress.

MisAdventure

there are two little 6mm nuts that hold that black box onto the alternator, I know because mine has one, I cleaned the terminals with sandpaper before reconnecting them, when I changed my alternator. Just saying the other side might be corroded as ****.

hotrod6657

Thanks for the heads up. Im in the middle of that midwest snow storm from a few days ago so as soon as the snow gets out of here or I find a warm place to work I'll see what I can find

hotrod6657

Okay, it's been awhile and the Jeep is still misbehaving. No solution yet, I just wanted to give an update.

the weather finally seems to have broken so I spent about 2 hours after work "playing around" with the wires that are believed to be suspect.

I've unwrapped the mini harness that goes to the alternator. There are three wires in the bundle. On large 0 or 00 battery cable style wire, one dark green wire, and one dark green with a red stripe.

Haynes manual says the green and red one goes to the injectors, solid green to the ECM (though I don't know what port/connector).

If I move the two thinner wires I can get the cutout to happen. I can't figure out which one is doing it though, since both seem to cause the stalling condition.

The wire going to the ECM (i believe) enters a small junction that appears to be factory shrink wrapped but I don't know.

I would rather figure out what's going on before I start clipping and splicing wires, but I"m running out of ideas.

If tomorrow is as nice as today I may bite the bullet and splice in a new section as far back as I can and hope i catch the problem section.

I love this Jeep but these sort of things drive me crazy!!!(with all vehicles, not just this one...) I just want to fix it so I can get on with "fun" modifications

Any insight or sympathy is appreciated lol.

hotrod

captainwoot

The dark green/red (is prob orange) is the wire that give B+ to the injectors . if this wire shorts anywhere in the circut it will cause your "cut out"

cavity 12 of the c3 connector

cavity 10 of the c2 connector


Hope these help....Good luck!
Note the splices s101, s122

hotrod6657

That looks very much like what the schematic in the Haynes manual showed.

Is it likely that the wire to the ECM would not cause such a sudden cut out?

I did check the resistance across the wire to the injector while trying to "jiggle" the wire (very scientific i know... lol) and the resistance remained low to negligible. It's totally conceivable though that the voltmeter I was using just doesn't react fast enough to see the break in conductivity.

If I do get out the wire cutters, shrink wrap, and heat gun I'll start with that one first just in case it's that's simple.

Thanks for the schematic.

hotrod

freegdr

http://www.cherokeetalk.com/forum/f2...ernator-12032/

hotrod6657

that was the impression I got when I took a close look at the box today.

Presently it seems like that box is not the problem, but knowing that I can simply bypass it is good. I may do that rather than try to splice it back in to the silly little black box.

Trick might be figuring out which wire goes to which port on the alternator.

freegdr

another possibilty is the connectors could be shorting out a gaints alt causing a pos to ground action on back of alt maybe

hotrod6657

Okay folks, success! (sorta)

I cut out the split that sends the green and red wire to the coil and to the ecm and spliced in a new wire. That didn't work. Still got the same cutout randomly when I jiggle the wires.

Poked around for about 2 hours and finally figured out how to get the plug that plugs in to the coil partially apart and confirmed an earlier suspision. The green and red wire in to the coil is pretty bent up and kinked. I straightened it out, left the alternator unplugged, and started the engine. Started fine but I could get it to miss and die by playing with the wire to the coil, near the coil connector.

That pretty much narrows it down, I'm fairly sure it's the coil connector, but the real question is how to I fix that? The ultimate would be a pigtailed replacement connector, but I've got my doubts that exists and I would be surprised if a junk yard/u pull it would let me cut up a harness...

I did get the connector put back together and spliced in extra wire so that the wire wasn't pulling like it was before and it seems to be fine, but I know it's just a matter of time until it comes back.

Well, there you go lol. Anyone have suggestions now lol?

Thanks,

hotrod

hotrod6657

Not trying to jynx myself but so far so good still. I know this isn't a proper fix but it should have bought me some time.

Does anyone know of a place to buy a new wiring harness? I would just need the powertrain harness (i believe) but I'd have to look more carefully to see what else I need to disconnect to get this part out.

I'd rather not bother with a used one, just because I don't want any new and exciting problems to come around because of it.

Motor in mine is a 97' 4.0L, the Jeep itself is a 96' (factory 4.0L). I know that the crank sensor at the very least is the one that would be on a 97' so I would assume the engine wiring and connectors should be 97' spec.

BTW, if anyone has an old previously cut up harness laying around and wouldn't mind lobbing off the coil connector and charging section I'd be willing to talk about buying it off you. (just something to think about)

hotrod


EDIT:

What do you think the odds are of a junkyard letting me cut up a harness to get at "new" connector? I've never requested anything like that before.