Refrigerant Pressure Sensor / Switch: Description and Operation

How the Climate Control Circuit Works

The climate control unit controls the blower controls, air delivery, and A/C compressor controls either automatically or semi-automatically. The control unit receives battery voltage at all times through fuse 13. With the ignition switch in ON (II), battery voltage is supplied through fuse 3. The control unit is grounded at G401.

A/C Pressure Switch

The A/C pressure switch is located in the condenser outlet line where refrigerant is in a high temperature/high pressure liquid state. The switch will sense abnormally high or low pressure, and open the circuit. This removes ground from the PCM, and turns off the compressor.