Just so everyone knows, I replaced the heater control unit on my '05 GP and that fixed the A/C always on problem. They are available on eBay used for about $40 or so, including shipping. Mine came off an '06 GP and it fit into the dash just fine. That was easier than taking the old heater control apart and desoldering and replacing the switch, but probably also more expensive. The momentary contact switches on these units seem to have issues after being repeatedly pressed numerous times! It took less than 10 minutes to swap in the new unit for the old.
