How to Determine Compressor Damage?
3 Answers
Methods to determine compressor damage: 1. Check if the input power circuit has electricity; 2. Inspect compressor accessories, including thermal protection and relay. Damaged thermal protection will prevent the compressor from receiving power, while a faulty relay will cause the motor not to rotate and emit a humming sound when powered on. In such cases, the machine should be stopped immediately; 3. Examine whether all connector contacts are intact and if plugs are tightly fitted without looseness; 4. Check if the circuit voltage is normal; 5. Verify if the temperature relay contacts are connected by removing the relay box cover to inspect the contacts. A compressor is a driven fluid machine that converts low-pressure gas into high-pressure gas, serving as the heart of a refrigeration system. It draws in low-temperature, low-pressure refrigerant gas through the suction pipe, compresses it via piston movement driven by the motor, and then discharges high-temperature, high-pressure refrigerant gas through the discharge pipe, providing power for the refrigeration cycle.
With years of experience in car repairs, I determine compressor damage through several key steps. The most obvious sign is when the AC fails to cool—if cold air doesn’t come out or is weak after turning on the AC, the compressor is likely the culprit. Listen for unusual noises in the engine bay, such as grinding or humming sounds upon startup, indicating internal part wear. Check the AC system pressure using gauges on the high and low sides; abnormal pressure (too high or too low) often points to compressor failure, common in older cars or after long drives. Visually inspect for oil stains or refrigerant leaks around the compressor, which suggest seal failure. Excessive vibration or a disengaged clutch may indicate shaft issues. Regular checks, especially in hot seasons, are advised to avoid complete system failure and costly repairs. For safety and optimal performance, a professional diagnosis is best—a faulty compressor not only reduces AC efficiency but also strains the engine.
As an average car owner, last month my AC suddenly stopped cooling and the fan blew hot air, making me suspect the compressor was faulty. After starting the engine and turning on the AC, I waited several minutes but it didn’t get cold, which felt abnormal. Then, I listened for sounds and heard a harsh metallic scraping noise from the engine bay. After parking, I checked the compressor area and noticed slight vibrations. Later, a friend mentioned leaks are also common, and upon inspecting the connections, I found oily stains, confirming refrigerant leakage. I tried checking if the belt was loose myself, but lacking expertise, I took it to a shop for a pressure test, which revealed internal compressor blockage causing failure. The solution was to repair or replace it promptly—delaying to save money could damage other components like the condenser. Regularly monitor AC performance while driving; if issues arise frequently, inspect early to avoid unexpected breakdowns.
