Refrigerant Pressure Sensor / Switch: Description and Operation

A/C Low Pressure Switch:

LOW-PRESSURE CUT-OFF SWITCH
Compressor protection is provided by a low-pressure cut-off switch on vehicles equipped with the V-5 compressor. Normally open, this switch will close above 324 kPa (47 psi) and will reopen below 255 kPa (37 psi).