77 280Z Air Con wiring - Thermostat issue?

[atariangamer]

Hello all,
New to Z Cars but am well underway with my 77 Restomod. After a bunch of trouble I've got my car rewired with a new harness, but since I'm down in the South, I kinda need my air conditioning working for any summer driving.

 

My understanding of the compressor switch circuit is that 12v goes through the vacuum source magnet valve, then goes in to the AC/Heater sub harness. It then goes to two places: the Fan switch, to activate vacuum for the system only when the fan is actually on, and to the microswitch for the A/C mode select. After the A/C microswitch is closed, it next goes through the thermostat switch. Basically, if the detected temperature is higher than the selected temperature, the switch closes, and you move onwards. It then checks if the system is pressurized via the pressure switch on the Receiver drier, before looping it back into the compressor relay, which will close and send 12V into the compressor clutch.

 

For the time being, I'm bypassing the vacuum tank system and just constantly feeding vacuum to the HVAC system. Once I get the car more buttoned up and ready for running/tuning, I'll get the check valve, magnet valve, etc. re-installed. And since I'm using an aftermarket receiver drier, I don't have the pressure switch. I'm running the line directly through the two switches: A/C mode select, and thermostat switch. If I put it in AC and push the temp slider to one extreme, it completes the circuit, flips the relay, and engages the compressor clutch.

 

However, when I finally got the faceplate for the air controls back on, I was confused to find that the extreme it activates on is the *hot* side.

 

Do the thermostats often go bad? Or is there some way to adjust it? I've tested that it properly controls the water heater valve, but for some reason it only sends the A/C signal when thermostat is moved to hot side, not cold.

 

That or if anyone can give me a better pin-out for the A/C harness, I may just have it wired up wrong.