What are the reasons for a car air conditioner hissing and not cooling?

[MacColton]

Car air conditioner hissing and not cooling reasons are: 1. Lack of refrigerant, leading to insufficient refrigerant in the air conditioning system pipelines and reduced pressure; 2. Long-term lack of maintenance, causing clogged air filters and condensers; 3. Air conditioning compressor failure; 4. Loose compressor drive belt, reducing compressor speed; 5. Poor remote control or faulty air conditioning receiver; 6. Four-way valve or compressor high-low pressure gas mixing, rendering the air conditioning ineffective. The air conditioner is used to adjust and control the temperature, humidity, air cleanliness, and airflow within the car cabin to an optimal state. Functions of the air conditioner: 1. Achieve cooling effect through the continuous phase change cycle of refrigerant; 2. Remove dust, odors, smoke, and toxic gases from the car's air, making the interior air fresh; 3. Humidify the car's air, increasing the relative humidity inside the vehicle.