Compressor Clutch: Description and Operation

CIRCUIT OPERATION

A/C Compressor Clutch
With the engine running, battery voltage is applied to the A/C switch, the A/C triple pressure switch (M/T) or A/C dual pressure switch (M/T), the coil of the A/C compressor relay and the air selector knob. When you press the A/C switch, battery voltage is applied to the electronic thermostat. The solid-state switch in the electronic thermostat closes, providing a path to ground for the thermo switch relay, with the fan control switch in any position except OFF. Voltage is also applied through the A/C triple pressure switch (A/T) or the A/C dual pressure switch (M/T) to the coil of the thermo switch relay. This closes the thermo switch relay contacts, applying battery voltage to the A/C ON input of the engine or powertrain control module (ECM or PCM). The ECM or PCM then provides ground for the A/C compressor relay. The A/C compressor relay contacts close, applying battery voltage to the compressor clutch. If the A/C triple pressure switch (A/T)/dual pressure switch (M/T) opens, the compressor clutch disengages.

The magnetic clutch connector is a waterproof type.

Magnetic Clutch

Magnetic Clutch:

The compressor is driven by the drive belt from the crank pulley of the engine. If the compressor is activated each time the engine is started, this causes too much load to the engine. The magnetic clutch transmits the power from the engine to the compressor and activates it when the air conditioning is ON. Also, it cuts off the power from the engine to the compressor when the air conditioning is OFF. Refer to Compressor for magnetic clutch repair procedure.