Order of execution
1. Install pressure gauges on the line.
2. Check the tension of the compressor drive belt.
3. Start the engine, let it run at 1500 rpm–1.
4. Check the compressor for the following defects:
- low pressure gauge reading, however, not lower than required, and high pressure gauge reading, however, not higher than required;
- metallic sound;
- leakage from the shaft seal.
If there is any defect, the compressor must be repaired.
5. Check the electromagnetic clutch:
- lift the car;
- inspect the pressure plate and rotor for grease;
- check the clutch bearing for noise and lubricant leakage;
- Measure the resistance of the coil with an ohmmeter.
If the resistance is not as specified, replace the coil:
- Using an additional wire, apply voltage from the positive terminal of the battery to the contact of the coil connector, while the electromagnetic clutch should be energized.
If the electromagnetic clutch does not energize, replace the coil.
Coil resistance: 3.11±0.08 ohm at 12.8V and 20°C