Execution order
1. Install pressure gauges on the line.
2. Check the tension of the compressor drive belt.
3. Start the engine and let it run at 1500 rpm.
4. Check the compressor for the following defects:
- a low pressure gauge reading, but not lower than required, and a high pressure gauge reading, but not higher than required;
- metallic sound;
- shaft seal leaks.
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;
- use an ohmmeter to measure the coil resistance.
If the resistance is different from the required one, replace the coil:
- using an additional wire, apply voltage from the positive terminal of the battery to the contact of the coil connector, and the electromagnetic clutch should be excited.
If the electromagnetic clutch does not excite, replace the coil.
Coil resistance: 3.11±0.08 ohms at 12.8V and 20°C