I have been reading so much about this system and i am starting to understand it.
My temp control switch(no manual control) only makes the whirring sound when in defrost mode. In auto, high or low it doesnt seem to do anything.
There is a vacuum actuator above the left side of the glovebox with a green line to it. When I switch modes and this moves it seems stuck then moves with a metalic scraping sound. It looks like i have to remove the dashpad to see it, is that correct? If so, how does the dash pad come off? I have L and R under dash panels off as well as instrument cluster and glovebox.

 

I removed the 3"wide rubber pad covering the demister doors. They look missaligned and the foam is falling off. These are the flaps that are making the metalic sound when they move. They are flaps with holes in them so I might disconnect them to avoid having to remove the dash to fix them. Does antone know if this would cause a problem?
I also checked the temp control and found resistance to be erratic when rotating it. I removed it, opened it up and cleaned the resistor and wiper then applied grease to it. It now goes smoothly from 0ohms to 9.8 kohms. I hope this solves my temp control issue. A coworker has an 85 that he is making into a race car and he said i could have his climate control amplifier.