Compressor Clutch: Testing and Inspection

ON-VEHICLE INSPECTION
TESTING THE MAGNETIC CLUTCH
HOW IS THE MAGNETIC CLUTCH ENERGIZED?
The general process until the magnetic clutch is energized as shown below.






1. Check compressor drive belt tension.
2. Start engine.
3. Check the clutch bearings for noise and leaking grease.
(1) Check for abnormal noise from the compressor when the A/C switch is off.
(2) If abnormal noise is being emitted, replace the compressor pulley bearing or magnetic clutch.
4. Stop engine.
5. Make the following visual checks.
(1) Leakage of grease from the clutch bearing.
(2) Signs of oil on the pressure plate or rotor.
Repair or replace, as necessary.
4. Using an ohmmeter, measure the resistance of the stator coil between the clutch lead wire and ground.
Standard resistance: 3.23 ± 0.08 Ohms at 20 °C (68 °F)
If resistance value is not as specified, replace the coil.
5. Connect the positive (+) lead from the battery to terminal, check that the magnetic clutch is energized. If magnetic clutch is not energized, replace the coil.

CAUTION: Do not short the positive (+) lead wire on the vehicle by applying battery voltage.