Why Does the Car Air Conditioning Compressor Cycle On and Off Repeatedly?

[MacCali]

There are primarily two specific reasons for the repeated cycling on and off of a car's air conditioning compressor: 1. First, observe whether the air conditioning fan is operating normally. If the fan is running, it indicates that the compressor may have malfunctioned. 2. The compressor could be damaged or the overheating protection function may have been activated. Additional information: 1. The car air conditioning compressor is the heart of the car's air conditioning refrigeration system, responsible for compressing and transporting refrigerant vapor. Compressors are divided into fixed displacement and variable displacement types. Based on their working principles, air conditioning compressors can be categorized into fixed displacement compressors and variable displacement compressors. 2. Depending on their operation methods, compressors can generally be classified into reciprocating and rotary types. Common reciprocating compressors include crankshaft connecting rod and axial piston types, while common rotary compressors include rotary vane and scroll types.

[VonKathryn]

I've seen many cases where a car's air conditioning compressor repeatedly starts and stops, usually due to abnormal system pressure. For example, if the refrigerant is too low or leaking, the compressor activates the protection mechanism and shuts down automatically when the pressure drops. When the pressure rises again, it restarts, creating this repetitive cycle. Of course, it could also be caused by too much refrigerant or a system blockage, such as a dirty expansion valve or clogged piping, leading to high pressure triggering the shutdown protection. I recommend first checking the air conditioning pressure with a gauge to see if the high and low pressure readings are within the normal range. Typically, normal low pressure is around 1.5-2.5 bar, and high pressure is 15-20 bar. Additionally, a faulty thermostat may misjudge the temperature, causing the compressor to start and stop irregularly. Ignoring this issue could lead to faster compressor wear, increased noise, or even complete system failure. If this happens, it's best to turn off the AC, open the windows for ventilation, and visit a professional repair shop as soon as possible for diagnosis—they can test for leaks or clean the system. Regular maintenance of the AC filter can also help prevent similar issues.