What are the symptoms of a faulty electromagnetic valve in a car air conditioning compressor?

[OAaron]

Symptoms of a faulty car air conditioning compressor: abnormal noises, insufficient power generation from the alternator, excessive pressure in the air conditioning system, or excessive engine load, the air conditioning system not working, or poor lubrication of the compressor. It is recommended to go directly to a 4S shop for inspection and repair. Below is additional information: 1. Classification of compressors: The car air conditioning compressor is the heart of the car air conditioning refrigeration system, responsible for compressing and transporting refrigerant vapor. According to different working principles, air conditioning compressors can be divided into fixed displacement compressors and variable displacement compressors. Based on different working methods, compressors can generally be divided into reciprocating and rotary types, with common reciprocating compressors including crankshaft connecting rod type and axial piston type, and common rotary compressors including rotary vane type and scroll type. According to different working principles, air conditioning compressors can be divided into fixed displacement compressors and variable displacement compressors. 2. Fixed displacement compressor: The displacement of a fixed displacement compressor increases proportionally with the increase in engine speed. It cannot automatically change power output based on refrigeration demand and has a significant impact on engine fuel consumption. Control is generally achieved by collecting temperature signals from the evaporator outlet. When the temperature reaches the set value, the compressor's electromagnetic clutch disengages, and the compressor stops working. When the temperature rises, the electromagnetic clutch engages, and the compressor starts working. The fixed displacement compressor is also controlled by the air conditioning system pressure; when the pressure in the pipeline is too high, the compressor stops working. 3. Variable displacement compressor: The variable displacement air conditioning compressor can automatically adjust power output based on the set temperature. The air conditioning control system does not collect temperature signals from the evaporator outlet but controls the compressor's compression ratio based on pressure change signals in the air conditioning pipeline to automatically adjust the outlet temperature. During the entire refrigeration process, the compressor is always working, and the regulation of refrigeration intensity relies entirely on the pressure regulating valve inside the compressor. When the pressure in the high-pressure end of the air conditioning pipeline is too high, the pressure regulating valve shortens the piston stroke inside the compressor to reduce the compression ratio, thereby lowering the refrigeration intensity. When the high-pressure end pressure drops to a certain level and the low-pressure end pressure rises to a certain level, the pressure regulating valve increases the piston stroke to enhance the refrigeration intensity.