How to Check the Condition of a Car Compressor?

[HarperMarie]

There are three main aspects to check the condition of a car air conditioning compressor: 1. Checking the compressor's sealing: Use a manifold gauge to test by connecting the high and low-pressure hoses of the manifold gauge to the compressor's high and low-pressure service valves, respectively. Start the engine and let it run at an idle speed of 2000r/min. 2. Measuring the resistance value of the compressor's electromagnetic clutch: First, remove the electromagnetic clutch coil from the compressor, then measure its resistance with a multimeter. Since the standard resistance of the electromagnetic clutch coil is (3.7±0.2)Ω, use the ohmmeter function of the multimeter to avoid measurement errors. If the multimeter needle does not move during measurement, it indicates that the electromagnetic clutch coil is open. If the measured value is less than 3.5Ω, it means the coil is short-circuited, open, or the electromagnetic coil should be replaced. 3. Checking the operating condition of the compressor: Whether the drive belt is broken or loose—if the drive belt is too loose, it will slip, accelerate wear, and fail to transmit power; whether there is noise inside the compressor; whether the compressor clutch is slipping.