Looking for some info on the AC compressor functions of a Ph2 172. For context, I've recently replaced the TX, dryer, pressure switch, condenser and compressor on a car I'm recommissioning after ~15 years off the road. System is gassed and lubed, no leaks, and blowing icey cold in the cabin. Functions on the climate control unit inside the car seem to be operating as per factory, too.
First question - Am I right in saying the compressor should cycle on and off in response to evap temps/pressures?
Second question - If my compressor is not cycling when set to cold (compressor clutch is engaged and running constantly), what are the likely culprits? Have tested the relay, cabin temp sensor and evaporator probe, and all seem to be functioning normally. Relay is definitely okay, and the other two are showing varied resistance when bench tested (assuming they combine to provide a signal for the ECU to shut off the compressor when cold enough?)
If anyone has any concrete info on how the AC/climate control system actually works, or any knowledge of known faults etc, I would be very grateful!
First question - Am I right in saying the compressor should cycle on and off in response to evap temps/pressures?
Second question - If my compressor is not cycling when set to cold (compressor clutch is engaged and running constantly), what are the likely culprits? Have tested the relay, cabin temp sensor and evaporator probe, and all seem to be functioning normally. Relay is definitely okay, and the other two are showing varied resistance when bench tested (assuming they combine to provide a signal for the ECU to shut off the compressor when cold enough?)
If anyone has any concrete info on how the AC/climate control system actually works, or any knowledge of known faults etc, I would be very grateful!
