Here is how I installed OEM cruise control onto my Liberty. It is plug and play and does NOT require a trip to the dealership to activate it. Here is what you'll need:
OEM Air Bag wiring - 68020374AA
http://www.tascaparts.com/oe-mopar/68020374aaOEM Cruise Control Switch - 4671929AC
http://www.tascaparts.com/oe-mopar/4671929AC2 - #10 screws 1/2" length
http://www.lowes.com/ProductDisplay?par ... &cId=PDIO11) Disconnect the negative terminal of the battery and leave it off. Step on the brake pedal a couple times to be sure there is no power left in the system. You'll be removing the airbag so you want to be sure there is no power.
2) Move the steering wheel to its most upward position and reach under the steering column and pull toward you to disengage the 2 clips on the knee trim panel under the column. It should swing down and out of the way like this:
3) Remove the 3 T-20 screws on the bottom of the trim that covers the steering column and separate the two trim pieces. They just snap together. You'll need to put the steering column adjusting lever to bottom position to get the bottom part of the trim off.
4) Insert the keys and turn it to the on position. Rotate the steering wheel so you can access the 3 air bag catches on the back of the steering wheel. Using a small mirror and a short flat head screw driver, move the catches off their perches. I put light pressure on the airbag to help pop it off the perches. The picture isn't great but I highlighted the air bag catches in red in the picture below.
5) Disconnect the 2 air bag connectors on the back of the air bag (1 yellow & 1 black) and set is aside. Disconnect the horn wiring harness circled in red below:
6) Cut a square hole in the side of the steering wheel. It's just foam so it was easy to cut it with a razor blade.
7) Squeeze the switch into the hole and carefully screw the 2 #10 screws. I say carefully as you'll see below where I broke the head off one on my screws and had to search my toolbox for a replacement. Connect the new harness (68020374AA) to the cruise control switch, horn connection and white clock spring connection on the top of the steering wheel.
Reinstall the airbag, steering column trim and knee panel and reconnect the negative battery terminal and you're all set. Total cost $43 plus shipping.