Compressor Check on Vehicle

PROCEDURE

1. Connect the manifold gauges to the lines.
2. Check the compressor drive belt tension.
3. Start the engine and run it at 1500 rpm.
4. Check the compressor for the following defects:
– low gauge reading, but not lower than specified, and high gauge reading, but not higher than specified;
– metallic noise;
– leaks from the shaft seal.
If any defect is found, repair the compressor.
5. Check the electromagnetic clutch:
– raise the vehicle;
– inspect the pressure plate and rotor for grease;
– check the clutch bearing for noise and lubricant leakage;
– measure the coil resistance with an ohmmeter.
If the resistance differs from the specified value, replace the coil:
– using a jumper wire, apply voltage from the battery positive terminal to the coil connector terminal; the electromagnetic clutch must engage.
If the electromagnetic clutch does not engage, replace the coil.
Coil resistance: 3.11±0.08 ohms at 12.8 V and 20 °C