Chrysler Repair: operation of ac compressor is intermittent, auto wrecking yards, salvage yards

Question
Re: 2001 Sebring conv (2.7 L): There seems to be a contact problem in the ac/heat switch on the dashboard above the radio. The compressor comes on fine in defrost mode. But in any of the standard ac modes, the fans blows, but no compressor. However, if I mess around with that selector switch (pushing it in and side to side), the compressor will often come on, but only for a minute or two. Suspecting that something wasn't making contact, I have had the unit out and apart three or four times but, try as I may, I can't isolate the problem. It is not too complicated--just a little disk with a couple of tracks that the metal contacts ride along. I've tried tweaking the contacts and so, on, but to no avail so far. So, do you think I should shop the salvage yards for that whole control unit...or prepare to spend an arm and leg at the dealer? Or is there more I can do to get the thing to make contact? Also, what part am I asking for--what would it be called? Thanks.

Answer
Hi Ed,
About the only other thing to try is electrical circuit board cleaner in a spray can. It would be available at an electronics supply store and you would spray it on the contacts of the control switch which are involved in activating the AC compressor via a signal to the body control module. You might also check the resistors to which those specific contacts are attached and also the solder joints between the resistors and the switch contacts. You may have a cold solder joint rather than a bad switch contact. Use a pencil-type soldering device to reheat the joints.
Because you have the unit out and can service it, if you can't reliably repair it then I would be inclined to go to auto wrecking yards, pariticularly  pull-it-yourself type, and get a new control unit. The switch is probably not available as a replacement part from a dealer but in any case it would be called the "mode switch".
Roland