The A/C compressor is a pump that compresses refrigerant. It is driven by the engine accessory drive belt. When the compressor clutch is OFF, the rotor pulley and armature plate are disconnected and the compressor does not operate. When the compressor clutch is ON, the field coil is energized, creating a strong magnetic field. This magnetic field locks the rotor pulley and armature plate together, driving the compressor. The compressed refrigerant becomes a high pressure and temperature vapor that is sent to the A/C condenser.

A/C compressor has a mechanical relief valve, and the valve opens when pressure exceeds the rated value. It cannot be reused, and should be replaced.

NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model.