A/C Low Pressure Switch

LOW REFRIGERANT PRESSURE SWITCH
The low refrigerant pressure switch is located in the low pressure refrigerant line. When pressurized, the switch is closed and allows the compressor clutch relay to energize, feeding battery voltage to the compressor clutch coil. If the pressure drops below 2 psi, the switch opens and cuts off voltage to the clutch. There is a circuit to the Air Conditioning Programmer (ACM) which monitors the state of the switch for diagnostic purposes.