Why Does the Car Air Conditioner Blow Hot Air?

[ChristopherMarie]

There are several reasons why a car air conditioner might blow hot air: 1. Forgetting to press the 'AC' button. AC stands for the air conditioning cooling function, and the compressor only starts working when this button is engaged. 2. Overheating protection of the car air conditioner compressor. This protection mechanism safeguards the refrigeration cycle system. If the compressor's casing temperature rises abnormally, the thermal protection switch on the compressor will trip, stopping the compressor. 3. Lack of refrigerant. Insufficient refrigerant is a common cause of air conditioner failure to cool. 4. Dirty radiator and condenser, affecting the heat dissipation cycle. In such cases, the surfaces of the condenser and radiator need to be cleaned. 5. Malfunction of the cold/heat switch. Although the heat sources for cooling and heating in a car are different and located in separate air boxes, they share the same fan and air duct. The cold/heat switch controls a flap that determines whether the air blown by the fan passes through the heater core or the air conditioner's evaporator into the air duct.