What Causes Frequent Cycling of Car Air Conditioning Compressor?
3 Answers
There are several reasons for frequent cycling of a car air conditioning compressor: 1. Activation of the car air conditioning's energy-saving mode. When the temperature rises significantly above the set temperature, the system restarts to bring it back on track. Many Japanese car models have this energy-saving mode, which is normal operation and doesn't indicate compressor issues. 2. High discharge pressure or low suction pressure. Moisture in the system can cause pipe blockages leading to icing. 3. Insufficient or excessive refrigerant. The amount of refrigerant determines system pressure, and abnormal pressure can cause frequent compressor cycling. 4. Relay setting limits are too high. If the high/low pressure limit values are set too high, the relay will automatically cut off when voltage slightly exceeds the threshold. Adjust by slightly increasing the high-pressure relay limit and decreasing the low-pressure relay limit.
Seeing the air conditioning compressor frequently starting and stopping makes me shake my head. This is a pretty common issue. Most likely, it's due to insufficient refrigerant—low pressure causes the compressor to cycle on and off. A faulty temperature sensor can also lead to repeated starts if the system misjudges conditions. A dirty or clogged condenser or a malfunctioning fan can cause overheating and force the compressor to restart. In our repair shop, we often see car owners neglecting these small details, only to face bigger, costlier repairs later. It's especially uncomfortable during summer when the AC is needed. I recommend checking the refrigerant level, temperature sensor, and fan operation right away—don't wait until you're stranded on the road. Regular maintenance can greatly reduce such issues, and simple tasks like replacing the air filter shouldn't be skipped. Safety comes first—excessive wear on the compressor could lead to a complete failure, and that won't come cheap.
I drive an old car that's over ten years old. Recently, the air conditioning compressor kept turning on and off non-stop, which distracted me while driving. After checking, it turned out to be a refrigerant leak—the low pressure caused it to cycle repeatedly. The thermostat was also aged and insensitive, and the fan was dusty with poor heat dissipation, causing the compressor to overheat. The mechanic said it could also be due to system blockage or electrical circuit failure. I endured the heat on a long trip and almost got into danger. Later, I replaced some parts, which cost me nearly a thousand yuan. So, it's really not worth delaying—early inspection is better. When washing the car, clean the condenser as well—it saves trouble, money, and energy, and reduces wear on the compressor for a longer lifespan. When it's hot, avoid driving too fast, and if the AC acts up, slow down.
