What Causes Frequent Cycling of a Car's Air Conditioning Compressor?

[OHazel]

Frequent cycling of a car's air conditioning compressor can be attributed to the following reasons: 1. Activation of the car AC's energy-saving mode: When the self-check temperature reaches the set target, the compressor shuts off to save energy. It restarts when the temperature rises significantly above the set point. 2. High discharge pressure or low suction pressure: Moisture in the system can cause pipe blockages leading to icing. This can be remedied by flushing the pipes with high-pressure nitrogen, adjusting the suction pressure by increasing the expansion valve opening, and reducing discharge pressure by increasing cooling water flow. 3. Incorrect refrigerant charge: The amount of refrigerant determines system pressure. Abnormal pressure levels cause frequent compressor cycling. 4. Improper relay settings: If the high/low pressure limit values are set too high, the system will shut off when voltage slightly exceeds these limits. Adjust by increasing the high-pressure relay limit and decreasing the low-pressure relay limit.