Kris4×4

I have a 96 Cherokee Sport that I'm having trouble diagnosing the problem with. My original issue was the ACHeat controls only worked on the high and low setting. So I replaced the blower motor switch and there was no change. I then replaced the resistor and that actually made things worse. Now only the high setting works and the defrost no longer works as well. I was going to replace the blower motor but I'm told because the low setting originally worked before I got started it couldn't be the motor. Rather than continue to make things worse as I go I figured it's time to stop and find someone with more expertise than myself. Any help would be greatly appreciated.

Kris

nujeepguy

are you looking at the wiring diagram?
the wire info in the haynes manual is helpful in figuring these things out. without a diagram your eyes are closed.
when i buy a new used car i stop at az on the way home and buy a manual for it. does a ok job for many jobs.

Kris4×4

Hey, thanks for posting! We have checked the wiring diagram. I made sure to tag all the wire placements before we unattached everything but when we started having trouble we pulled out the old Haynes manual. Checked and rechecked. Then we started checking vacuum lines because somebody said that was why the defrost quit working. So far we haven't been able to find anything out of place or unattached. About 10 yrs ago we had the exact same original problem with the jeep - contol switch only worked on high and low - and we replaced the whole panel from one we bought from a junkyard and it worked fine. Kind of wish I'd taken the same route this time.

Kris4×4

We've rechecked the wiring and bought an additional resistor because we had a feeling it might be faulty but we still have the same results. Just want to see if anyone else might have a suggestion before we take it to the shop.

Kris4×4

So I am at a loss. After a lot of trial and error I got it working. It worked fine until I put on the new resistor. I only put it on because I'd bought it and when I did that the only setting that worked was high. So I said to hell with that and just put the old one back on. Worked perfectly for about 10 mins. I had brought my daughter outside to show her the coils lighting up - it's gonna be her jeep - and while we're waiting for the third coil to light up it just stops working. Checked the fuses and the wiring and nothing is amiss.

HappyTrails

Check the integrity of the vacuum line that runs from the firewall, along the right inner fender, past the Cruise Control Servo, if you have that, and down to the vacuum reservoir tucked in the right side of the front bumper. (Looks like a small black football. sort of.) Make sure all connections are secure and the line is not punctured.

I just had to fix mine after something, maybe battery acid, really did a number on the plastic tube in about four places.

Cruise control and heater/ac controls were all messed up.

Replace the front three feet of the tube and all problems went away.

Good luck

Kris4×4

Thanks for all the assistance. I got kind of frustrated and moved on to rewiring the interior but now I'm back at the AC control panel and I think I've found the source of the problem but I'm not sure how to proceed. Btw, Defrost is fixed. It was a vacuum line. Thanks for the tip! So after replacing the relay, switch, and resistor, my dumbass decided to check the voltage coming in at the resistor. I have 12v on 3 of the 4 wires. The green wire has zip. I pulled the washer fluid reservoir and disconnected the blower motor to check for continuity from the motor to the resistor and I'm good there. And I know there is nothing wrong with the blower motor. I can get the AC Switch to operate on 3 out of 4 setting if I rig it and wire it out of sync, but I don't really want to do that. Any suggestions are appreciated!

Kris4×4

Nevermind, finally figure it out.