What are the reasons for the compressor not starting?

[McCaleb]

There are several reasons why a car air conditioning compressor may not start: severe internal wear of the compressor, leading to inability to function properly; insufficient refrigerant in the car air conditioning system; circuit system failure, etc. Factors such as insufficient refrigerant in the car air conditioning compressor, relay malfunction, pressure switch tripping, etc., can all cause the car air conditioning compressor to fail to engage. Additional information: 1. The car air conditioning compressor is the heart of the car air conditioning refrigeration system, responsible for compressing and transporting refrigerant vapor. Compressors can be divided into fixed displacement and variable displacement types. Based on different working principles, air conditioning compressors can be categorized into fixed displacement compressors and variable displacement compressors. 2. Compressors can generally be classified into reciprocating and rotary types. Common reciprocating compressors include crankshaft connecting rod type and axial piston type, while common rotary compressors include rotary vane type and scroll type.