Hey there Zenash,
Its the switch module (the stuff behind the knobs you tun to control the cabin temp). I have an '01 Sahara which just started doing the same thing. At first I was afraid my AC stopped working but after jacking round with the knobs, the unit will intermittently work....indicating that the system works, just not the controls. The dash is very easy to take apart.
From memory, its roughly as follows.
Start by popping out the grid that the defrost air comes out of. This is only held in place by retention clips. Under that grid you will find (2?) screws that attach the top of your center dash. unscrew them AND DO NOT DROP THEM into your air duct
Next, remove your ash tray (open it and push down on the lever inside like you were removing it to empty it) Once it is out you will see a screw which also needs to be removed.
Now the center dash will pop off (pull from the top towards you)
Once thats off, the temp control unit only has two screws to un-do.
All set form there!
The old/new modules will unplug and connect easily in the rear