merchauser

Not sure if there is a relationship between these two, but neither one is working. Fortunate to have another car nearby and I was able to do some swapping of components for testing:
HVAC control unit, AC switch/button, outside air temp sensor and inside air temp sensor all test good. (fuse #6 is good)

My next step is to remove and clean setting motor, and perhaps that will remedy that issue, but pretty sure the AC button gets power directly from the control unit and not the setting motor?

StratfordShark

The driver transistors are usual fail points of mixing motor. Easy to replace as lovely old school PCB with acres of room between discrete components.

merchauser

SOLVED! the six pole plug connector, behind the HVAC head unit was not fully seated in its connector; both AC switch and setting motor are working properly!

StratfordShark

Nice simple fix!