Just curious, why are you swapping out the Heat and AC Control Module? I have a heating and cooling problem that for a few days seemed to be related to my fiddling with the manual temperature knob. While it was initially acting up, I would get very hot air with the A/C ON and the temp set for cold, then later the A/C would work normally, now all I get is cold air. No heat at all. I have not pulled the unit out of the dash yet, that may be a task for next weekend.