Ac solenoid on thermoquad

To repeat, this was a "smog" device. It was to set idle speed and intended to close the carb at shutdown to try and reduce dieselling. My 70 440-6 had one, and the purpose of the large brass end where it rests on the throttle was with such engines as the 4bbl 440's which had a distributor solenoid. The throttle lever would ground the brass end, there was/ is a wire connection there, and that would activate the retard solenoid "at curb idle"

Actually you COULD repurpose this for AC. You would want to splice it into the AC clutch feed properly, upstream of the low pressure switch, which cycles the clutch off on low pressure

Frankly if you retune the engine, richen up idle, recurve the dist. and run more initial advance, etc etc, and do not have to have the car "smogged" I would simply remove the thing.

They were a PITA because most the time the solenoid did not have enough "oomph" to set the thing. You had to crack the throttle to set it. So they would almost never start and run just by turning the key