Cruise, A/C, ABS Electrical Problems

[LPelton]

93 Jeep Cherokee 4.0. All at the same time I lost my A/C system, my aux fan stopped, Cruise Control quit and the ABS light started shining on the dash. MIL codes are 33, 35, 36. When I turn on the A/C switch the engine speeds up like it is anticipating the clutch activation but nothing else happens. The clutch does not engage and the aux fan does not come on. I can jump the A/C relay and the clutch will engage (and cools) and the aux fan comes on. Fuses are all fine.
I have not done any troubleshooting on the cruise control yet. The ABS pump does not seem to be activating. I dont feel it vibrating anymore. I can reset the PCM and the ABS light comes on immediately. I am guessing there is one sensor common to all of these systems causing the problem. I checked the TPS and it seems to be fine. Not sure what else to check. I heard the wide open throttle relay might be bad but I dont think this vehicle really has one. I am beginning to think the computer may have gone bad. Any suggestions?

 

[Bounty__Hunter]

33* An open or shorted condition detected in the A/C clutch relay circuit.

35* An open or shorted condition detected in the radiator fan relay circuit.

I had a tough time finding anything on #36, only thing I found close to being related to your symptoms is:
36* A/C Request Signal Voltage Low

Have you replaced any of the relays to see if that fixed the problem? The AC and ABS relays are there together, and maybe the Cruise, so something could have damaged all of them at the same time.

I've got the cruise control solenoid from a '93 XJ I parted out, if you need it. A lot of other '93 XJ parts if you need anything else.

 

[LPelton]

RE: Re: RE: Chat room Sunday at 9:00 est

33* An open or shorted condition detected in the A/C clutch relay circuit.

35* An open or shorted condition detected in the radiator fan relay circuit.

I had a tough time finding anything on #36, only thing I found close to being related to your symptoms is:
36* A/C Request Signal Voltage Low

Have you replaced any of the relays to see if that fixed the problem? The AC and ABS relays are there together, and maybe the Cruise, so something could have damaged all of them at the same time.

IThanks, all the relays are good (I have not checked the ABS relay but it has power where it is supposed to). I did not try to take teh relay box apart to see if something was wrong inside. The incoming signal to the relays is what appears to be missing. The cruise control is only about 2 years old. That is why I am trying to figure out if it is a problem common to all three. Wide open throttle cutout for the A/C could be one but from what I can tell that is actually done by the computer. A brake switch seems to be common to the cruise and ABS system but not sure how the A/C ties in. Could be a problem in the wiring from the computer to the under hood relay/fuse box. When it stops raining long enough I am going to jump a wire from the computer output connector to the relay and see if it works. With such a wild range of problems (and it is very hard to get the MIL to flash consistent codes) I still have the bad feeling it is the computer. It was replaced a few years ago. Any ideas?

 

[Bounty__Hunter]

RE: Opinions on thread

Sounds like it's upline from the relays then. Try to email or PM XJ_Nick on here, he's a go-to kinda jeeper for electrical issues.

 

[Saurian]

Re: RE: Opinions on thread

Is there one of those stupid maxi-fuses that might control those systems? Just a thought...

 

[LPelton]

RE: Iraqi Election

Is there one of those stupid maxi-fuses that might control those systems? Just a thought...

Thanks, I checked all the large fuses. All appear good. I may change them out anyway. Should have done a continuity test on them. I will send XJ Nick an email and see what he thinks. I will be away from the Jeep for a few weeks so I may have to try again after the 14th of Feb.

 

[LPelton]

RE: mildew smell coming out of the heater and water seepage

Thanks for everyones help. The solution was so simple I am almost afraid to post it. My mistake was that I only checked the fuses that were obviously part of the systems that weren't operating. For the heck of it I went down the entire under hood power center and checked every fuse. There is a small one marked "Ignition" It had blown. The second I replaced it everything was up and running. It always pays to check everything simple.