What are the reasons for a car's air conditioning not cooling?

[RiverRose]

Reasons for a car's air conditioning not cooling: 1. Insufficient or too little refrigerant: Simply add refrigerant; 2. Too much refrigerant: The proportion of refrigerant in the air conditioning system is specified. If the proportion is too high, it will affect heat dissipation. Slowly release some refrigerant at the low-pressure side maintenance port; 3. Loose drive belt of the car's air conditioning compressor: If the drive belt is loose, the compressor may slip during operation, reducing transmission efficiency, causing the compressor speed to drop and the delivery of compressed refrigerant to decrease, leading to the air conditioning not cooling. If the drive belt is too loose, it should be tightened. If it cannot be turned by hand, the belt is too tight and should be slightly loosened; 4. Unqualified refrigerant or refrigeration oil; 5. Moisture infiltration into the refrigeration system: Replace the desiccant or dryer in the car's air conditioning, evacuate the system again, and refill with the appropriate amount of new refrigerant.