Compressor Clutch: Testing and Inspection
ON-VEHICLE INSPECTION1. SET MANIFOLD GAUGE SET
2. START ENGINE
3. INSPECT COMPRESSOR FOR METALLIC SOUND
a. Check if a metallic sound can be heard from the compressor when the A/C switch is on.
If a metallic sound cannot be heard, replace the compressor assembly.
4. INSPECT REFRIGERANT PRESSURE
5. STOP ENGINE
6. INSPECT VISUALLY FOR LEAKAGE OF REFRIGERANT FROM SAFETY SEAL
a. Using a gas leak detector, check for leakage of refrigerant.
If there is any leakage, replace the compressor assembly.
7. REMOVE MANIFOLD GAUGE SET
8. CHECK FOR LEAKAGE OF GREASE FROM CLUTCH BEARING
9. CHECK FOR SIGNS OF OIL ON PRESSURE PLATE
If necessary, repair or replace.
10. INSPECT MAGNETIC CLUTCH BEARING FOR NOISE
a. Start the engine.
b. Check if abnormal noise is heard from near the compressor when the A/C switch is OFF.
If abnormal noise is being emitted, replace the magnetic clutch.
11. INSPECT MAGNET CLUTCH OPERATION
a. Disconnect the connector.
b. Connect the positive (+) lead from the battery to terminal 3 and the negative (-) lead to body ground.
c. Check that the magnetic clutch is energized.
If operation is not as specified, replace the magnetic clutch.
12. INSPECT COMPRESSOR LOCK SENSOR RESISTANCE
a. Disconnect the connector.
b. Measure the resistance between terminals 1 and 2.
Standard resistance: 165 to 205 ohms at 20 °C (68 °F)
If resistance is not as specified, replace the compressor.