Compressor HVAC: Testing and Inspection
COMPRESSOR1. Install a manifold gauge set.
2. Check the compressor drive belt tension.
3. Run engine at approx. 1,500 rpm.
4. Check the compressor for the following:
- Low pressure gauge reading is not lower and high pressure gauge reading is not higher than abnormal.
- Metallic sound.
- Leakage from shaft seal.
If any of the above is not satisfactory, repair the compressor.
5. Check magnetic clutch. Raise the vehicle.
- Inspect the pressure plate and the rotor for signs of oil.
- Check the clutch bearings for noise and leaking grease.
- Using an ohmmeter, measure the resistance of the stator coil be between the clutch lead wire and ground.
Standard resistance
3.11 ± 0.08 ohm at 12.8 V 20 °C (68 °F)
If resistance value is not as specified, replace the coil.
- 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.
NOTE: Do not short the positive (+) lead wire on the vehicle by applying battery voltage.