I have been having intermittant issues with my CC since I got my jeep, itll work for a couple weeks then it wont work at all, or it will turn on but goes off at random or if i hit a bump. I was reading on jeep forum that the cc is run through the brake switch (makes sense), I also noticed that when I go around a sharp turn at higher speed my brake lights come on without me touching the pedal. Could my brake switch be out of adjustment or gone bad? How do I test/adjust this?

 

i'm guessing it is similar to a XJ, so simply go to the brake pedal, look behind, there will be a switch that is held on by a plastic clip. all you have to do is push (or pull, can't remember) that clip in maybe 1 or 2 "clicks" and it'll be adjusted. in case you go too far, just pull (or push) on it to reverse the process.

edit: looking at parts online they seem to be a bit different,

here's the XJ one, notice the threaded part of the plastic, that's what i was referring to

http://www.rockauto.com/info/903/1S4999.jpg

here's the ZJ one, no threaded part, but the process might be similar

http://www.rockauto.com/info/903/1S4998.jpg

final edit: they seem to be self adjusting brake light switch.

https://www.youtube.com/watch?v=x-BYHle-rzo

 

Thanks. Ill look and see. I should also add that I dont think it is vacuum related as the system holds a vacuum to the point I can go out there an hour after shutting the jeep off and its still holding.

 

i had a similar issue in my XJ. i'd lose the cruise control when hitting bumps on the highway and after looking for a leak but not finding any, i tried the brake light switch trick and it took only 1 or 2 clicks, everything was then fixed.

 

If you're talking about holding brake vacuum, that's a separate unit in itself. I doubt the heater/cruise system holds vacuum more than a minute or 2. The cruise solenoid vents as soon as you turn the key off. The accumulator closes the heater doors at the same time.