What's the reason for a car's air conditioning compressor not starting?

[VonMalachi]

Reasons for a car's air conditioning compressor not starting: 1. Severe internal wear of the compressor; 2. Lack of refrigerant in the car's air conditioning system; 3. Circuit system failure. The car's air conditioning compressor is part of the car's air conditioning refrigeration system, responsible for compressing and transporting refrigerant vapor. Air conditioning compressors are classified based on their working principles into: 1. Fixed displacement compressors: Their displacement increases proportionally with the engine's speed, controlled by collecting temperature signals from the evaporator outlet and the air conditioning system pressure; 2. Variable displacement compressors: Their displacement automatically adjusts power output based on the set temperature, controlled by pressure change signals within the air conditioning pipeline.