StolenIce

Soooo my cruise control does not work (1999 Cherokee Sport). I apologize if you guys have seen this issue a million times before. I did a few searches but came up with nothing similar. I was looking through the "ask the questions" sticky but there are over 50,000 replies.

Anyway, the cruise control does not work. The Vacuum lines all seem the be holding pressure. It seams as if the button just does not do anything. It clicks, but nothing happens. My horn works fine. My HVAC controls work as expected. I did the test to check the cluster lights and the "cruise" does light up. I lifted the brake pedal up (at highway speeds) but still nothing.

I just don't know. Is there a fuse/relay i could replace? Do i need to take off the airbag to check the wires in the column?

Any ideas? Thanks!

toasterknight

Sounds like a clock spring dying mine did the same thing and that was exactly the problem. Yes my horn still worked.

XJ-kee

Your positive the vacuum/servo for the cruise control is working? Did you check the little servo by your battery? Could be anything from the cable attaching to the throttle body somehow got frayed or even broke, to a small leak in the vacuum line near the servo, to the servo actually not working at all.

How good are you with a multimeter? A good option to try right now is pull the airbag out and start probing the cruise control switches and see if you have continuity between the connections and checking to make sure that their resistance values are within tolerance.

StolenIce

Everything appears to be in working order but couldn't say for sure. I can handle a multimeter. Do you have a reference for what the resistance values should be?

cbs_24

Sorry to piggy back on your thread, but I'm having a similar issue. My cruise control does not work and I also have the airbag light on. Does that mean the clock spring is bad? And if that is the issue, does anyone know where to get one for Jeeps w/ cruise control? All the ones I have found are for Jeeps without it.

XJ-kee

Does your horn work? if not, almost a guarantee that it's the clockspring gone bad, as long as you dont have any other outstanding issues that you might know about. If you can't find one on ebay, it's time to start scouring craigslist to find a part out, or a junkyard near you.

1. The Cruise light comes on
2. Horn works
3. HVAC works
4. You checked the vacuum lines

However, it's very odd that your cruise light would work, but you can't SET the speed, since those are on the same switch. So either the "set" portion of that switch has gotten out of tolerance (or is dirty underneath and needs to be cleaned?) or something in the servo/vacuum line is still the problem. I would double, triple check to make sure that it's not any vacuum leaks at all beforehand to save yourself the time of pulling the airbag off, and possibly even the steering wheel. The cruise control servo is very easy to replace, and you can get them pretty cheap if there's a junkyard near you.

Resistance values:

StolenIce

Sorry, let me clarify a bit. The cruise control light only works when I tested all of the dash lights (basically the bulb is functioning)- not when I push the button. When I try and set the cruise it's like a dead button. It just doesn't do anything.
Is there any way to test the servo?
And thank you for the values.

cbs_24

The horn does work. It seems to just be the airbag light and no cruise control.

toasterknight

Thats what mine was doinng minus the airbag light. Clock spring fixed it.

StolenIce

Is it possible to test a clock spring?

toasterknight

I know you can manually bypass it and engage the cruise control at the pcm but I'm not sure which wire it is. Someone with more experience may have a diagram that will show you which wire to short to run it on.

StolenIce

Ok so with the multimeter I get 20k ohms with no buttons pressed. 500 with on/off. Only 4.4k-4.5k for the set. So the set is definitely not correct but does that matter? I didn't even test the others because the on/off was correct yet doesn't work. Leads me to believe that toasterknight is correct in saying it's a bad clockspring.
Sound reasonable?

cbs_24

I replaced my clock spring with a used one I purchased from Ebay and I have full cruise control functionality, as well as a working airbag again. Not a hard swap at all.

StolenIce

After working on the Jeep it turns out it was the clockspring. I disassembled it and 2 of the 5 wires in the ribbon had torn. Soldered it up, gave it a little tlc and reassembly and everything is working as it should. Even though I tested the clockspring with a multimeter multiple times I have to admit that I did start it up from the passenger seat, and drove it around sitting far from the steering wheel haha. Just in case

Thanks for all of the advice everyone