Air Conditioning Compressor Inspection Methods?
3 Answers
Automotive air conditioning compressor inspection methods are as follows: 1. For issues with the compressor motor, improper closing of the compressor suction and discharge valves, and thermal protector faults, replacement is the recommended solution. 2. For compressor shaft seizure or cylinder jamming faults, repair attempts can be made first. Specific methods include the following: 1. Tapping method. After starting, use a wooden hammer to tap the lower half of the compressor to vibrate the stuck internal components into operation. 2. Capacitor start method. A capacitor with a larger capacity than the original can be connected to the circuit for starting. 3. High-voltage start method. The power supply voltage can be increased using a voltage regulator for starting. 4. Pressure relief method. Start the compressor after completely releasing the system's refrigerant.
As a veteran truck driver with thirty years of experience, I know how frustrating it can be when the air conditioning compressor acts up. Before jumping into repairs, listening is key: after starting the engine and turning on the AC, the compressor should produce a regular humming sound—if it’s screeching or silent, that’s a red flag. Check the belt tension by pressing the midpoint; movement should not exceed half an inch. Replace cracked belts immediately to avoid breakdowns on the road. Next, measure the refrigerant pressure: 20-40 PSI (low) and 150-250 PSI (high) are standard. Too high suggests a clogged condenser, while too low indicates a leak. For electrical components, inspect the fuse and replace if blown. Test the relay and clutch coil resistance with a multimeter—normal readings should be 3-5 ohms. Safety first: avoid reckless disassembly. Clean the condenser annually to prevent dust buildup, and don’t forget gloves for grip. After servicing, test-run the system—only cold air confirms success.
I've been DIY car repairs for years, and inspecting the AC compressor isn't actually difficult. Open the engine hood, first check the belt tension - it's best if it doesn't wiggle, and replace the belt if there are signs of wear to prevent sudden breakage. Start the engine and turn on the AC, listen to the compressor's operation - clicking or squeaking noises may indicate bearing issues. Use a multimeter to measure the clutch resistance value; 3 to 5 ohms is normal, beyond this range means parts need replacement. Be careful with refrigerant system pressure testing - get a simple pressure gauge to connect to the high and low pressure ports for readings. Low pressure indicates refrigerant shortage, but don't add refrigerant yourself as it can easily pollute the environment. Clean oxidation from electrical connectors to improve conductivity, and regular maintenance of the cabin air filter can make the compressor last longer. Have your tools ready and don't be careless.
