Compressor HVAC: Testing and Inspection
On-vehicle Inspection1. Install the manifold gauge set.
2. Run the engine at fast idle.
3. Check the compressor for the following:
(1) High and low pressure normal.
Normal pressure: at 25°C (77°F)
Low pressure: 98-167 kPa (1.0-1.7 kg/cm2, 14-24 psi)
High pressure: 1,030-1,324 kPa (10.5-13.5 kg/cm2, 149-192 psi)
(2) Metallic sound from compressor. (Replace compressor.)
(3) Leakage from shaft seal.
Repair or replace as necessary.
4. Check the magnetic clutch for the following:
(1) Pressure plate and rotor for signs of oil.
(2) Clutch bearings for noise and grease leakage.
5. Check the resistance of the stator coil between the magnetic clutch connector and a ground with an ohmmeter.
Resistance at 20°C (68°F):
Nippon Denso compressor: 2.9 ohms
Sanden compressor : 3.05-3.35 ohms
If not as specified, replace the stator.