Compressor Clutch: Description and Operation

A/C Electrical Diagram:

The general process to energize the magnetic clutch is shown below
1. Ignition Switch "ON"
2. Blower Switch "ON"---> Heater Relay "ON" (Blower Motor "RUN")
3. A/C Switch "ON"---> A/C Amplifier "ON" (A/C Amp. Main Power Supply)
4. Dual Pressure Switch "ON" (Refrigerant pressure greater than 30 psi (206 kPa, 2.1 kg/cm2) and less than 413 psi (2844 kPa, 29 kg/cm2))
5. Thermistor supplies temperature signal of evaporator to A/C amplifier.
6. VSV "ON"---> Engine Idle Up
7. Magnetic Clutch Relay "ON"
8. Temperature Sensor "ON" (Sensor reading less than 180 degrees C (356 degrees F))
9. Magnetic Clutch "ON"
10. Revolution Detecting Sensor supplies RPM signal of compressor to A/C amplifier. If compressor is not locked, magnetic clutch is energized.