Caprice V8-265 4.3L VIN W MFI (1995)
A/C Signal: Description and Operation
A/C Request Signal
When the heater and A/C control is placed in the A/C Mode, a request signal is sent to the PCM. The PCM will then energize the A/C clutch relay,
unless abnormally high or low A/C pressure is detected by the A/C refrigerant pressure sensor. The PCM will also turn the cooling fans "ON" when A/C
is requested. The A/C clutch relay is controlled by the PCM so that the PCM can increase idle speed before turning "ON" the clutch or disable the clutch
during WOT, and high coolant temperature.
This system consists of a heater and A/C control, A/C pressure cycling switch, an A/C refrigerant pressure sensor, an A/C clutch relay, the compressor
clutch, and the PCM.
The A/C refrigerant pressure cycling switch is closed when there is sufficient system pressure (depending on refrigerant charge (R134a) and ambient
temperature).
