Bizarre:AC/Cruise Control on 1996 Xj

Hey all,
A few days ago something bizarre happened when I got into my Cherokee about to run some errands. I started it up and expected to be on my way...unfortunately that was not the case. The Jeep lurched forward nearly into the car parked in front of me. As it turns out since I had the AC still in the On position on the slide it for some reason engaged the cruise control with activation light and everything. So now anytime I put the slide anywhere from Max AC to Heat the Cruise comes on, but the air does not.

I removed most of the dash looking for possible shorts and found none. I suspected the wiring first because the previous owner installed his own stereo system. Now though I'm kind of amiss and not sure where to go from here. A few weeks out from class gives me precious little time to resolve the matter so any help would be appreciated. I could just not run the AC...but the Alabama summer has not been kind. (105 on the heat index today).

Thanks in advance for any insight or help on this matter.

1996, 4.0L Sport 4x4

Best Regards,
Hannibal

Have you been messing with the vac lines?

Negative, but I do recall scanning over something that mentioned vac lines, however none the articles were about my particular model. 1996.

A**uming automatic, you have your right foot on the brake, shift into gear and the cruise is engaged--start with the brake switch, it should PREVENT the cruise from being engaged, sounds like it is PART of the problem.

On a '96 - normal operation is the cruise system will turn on, BUT is blocked from engaging below 45 mph.

Also like Joe said about brake disengage, too.

---So something is really wrong.---

1. Remove cruise actuator, right behind battery until you can find a safe place to repair. Pull fuses for Cruise system.

2. Check the brake switch.

3. Check J/Y for replacement system prices. It may be faster, cheaper, and safer to just replace.

Be Carefull.

Good Luck,
Orange

Gotcha, and thanks for the recommendations. Is there anything though that overlaps the AC and Cruise systems? Like I said I pulled out the whole dash and all the wires were still insulated and I detected no shorts anywhere in the dash. All the fuses have been checked as well for both systems so I'm really at wit's end. Someone above mentioned vac lines, does anyone know which vac lines are responsible? I checked my Haynes and the only vac lines it mentioned were in 1984-89 models and four cylinders to boot.

Disconnect the battery, then unbolt and check the bottom of the PDC for possible corrosion.

Other than that check the brake switch and the components as Orange suggested.

Good luck.

I asked about the vac lines earlier because that's the only "overlap". The CC actuator is vacuum operated and so are the mode doors on the HVAC. Both get vacuum through the vacuum reservoir behind the front bumper.

So, hypothetically, if you crossed the HVAC line with the CC actuator line, once you start the engine, vacuum builds and *may* open the throttle.

There are 2 vac lines that exit the firewall. One goes to the reservoir, and the other to your heater valve. Make sure they look OK as well.