[goldensd]

I give up.. After two days of tearing everything apart, I can't find the issue..

Hopefully someone can help. Here's what's up.

For starters I had my '97 ZJ parked at the airport over the holidays, and when I got back the battery was dead, but nothing had been left on (weird #1).

It started right up with a jump, but then on the way home my guages started flashing on and off, the gauges, odometer, and all of the lights would randomly die out and come back (weird #2)

Then when I got home, I turned off the truck, but truck didn't turn off immediately, and power stayed to the dash (weird #3).

I thought maybe it was the ignition switch and tore that apart, but it seemed to check out, but I did find that power seemed to be backfeeding into the ignition/run wire. This should be dead without running thru the ignition switch. I traced this wire all the way to the fuse #1 in the PDC. I pulled the fuse, and it was fine. Put the fuse back in and now the engine starts and stops as it should, but I can't get the gauges to work at all now. I also found that the auto headlights don't seem to work. I've swapped all the relays around to check them, checked all fuses and circuit breakers. I've traced power thru all of the fuses that seem relevant to my issue and find power going into all of them.

The only other thing I can think of is the PCM, doesn't seem like that type of problem, but maybe. I think I'll pull mine and try it in a friends ZJ.

Does anybody have any other ideas??

 

[JayH]

Sounds like a bad ground somewhere. Start with the major ones in the engine compartment and work backwards from there.

 

[goldensd]

ground

I agree a ground seems reasonable, but I've cleaned all of them I could find or reach, and none really showed any signs of corrosion.

I've been trying to track them thru the schematics in my Haynes, but not having a whole lot of luck. Any ideas, where any more grounds might be outside of the engine compartment. Haynes says there is a ground on the right and left kick panels, but I can't find any, and I don't totally trust what I am seeing in the Haynes Schematics.

Any help is appreciated, I'm running out of patience quickly.

 

[JayH]

Yup, electrical problems are the worst and most difficult to track down. Lots of time and patience required.GL

 

[JimmyD-55]

I would try to eliminate all the other possible causes before trying your PCM in somebody Else's rig. Something may have caused your PCM to fail or it may have cause another component to fail. I'd hate to see you hook your PCM up and take out something on your buddies ride.

 

[CSCHOTT]

I had the same problem too just look what I found though.

http://www.pnwjeep.com/phpbb2/viewtopic.php?t=4659

Corey

 

[goldensd]

OH BOY!!!!

That is exactly the kind of help I am looking for, but it sure would've been nice to hear of a simpler thing. I did realize it was a bad idea to swap PCM's and didn't do that, but I am going to double check my instrument panel and headlight switch in another ZJ before fighting and further. I guess if they work, I'll have to tear into the fuse box, which looks like it will definitely give my patience a run for its money! Coincidently, my truck sat out in those heavy ass rains in California over New Years, which certainly added the H2O element to this.

Thanks for the info. Hopefully, I'm getting closer.

 

[goldensd]

Still trying!!

Well through trial and error on another ZJ, I thought I found the problem to be the body control module. Found one at a junkyard and had it shipped, but it didn't fix the problem. In fact, I can't keep the thing running with the new one in.

Does anyone know if you have to reset something, to change out a module like this?

I have now tried the headlight switch, instrument cluster, and pcm in another ZJ, and they all seemed to work fine.