What Causes a Car's Air Conditioning to Alternate Between Hot and Cold?
2 Answers
Car air conditioning alternates between hot and cold due to: refrigerant leakage, internal damage to the air conditioning pump, excessively dirty condenser fins in the air conditioning system, loose compressor wiring, poor contact of the pressure switch, electrical contact issues, excessive pressure in the air conditioning high-pressure pipe, or compressor clutch failure. Car air conditioning is designed to regulate and control the temperature, humidity, air cleanliness, and airflow within the vehicle cabin to an optimal state, providing a comfortable environment for passengers, reducing travel fatigue, and creating favorable working conditions for the driver. It serves as a crucial ventilation device for ensuring safe driving. Generally, car air conditioning includes cooling devices, heating devices, and ventilation systems. This integrated system makes full use of the limited space inside the vehicle, featuring a simple structure, and represents the internationally popular modern car air conditioning system.
Last time my car's AC had this issue, it was really annoying with the temperature fluctuating between hot and cold. Usually, it's due to insufficient refrigerant or a leak, causing unstable system pressure and inconsistent compressor performance. The temperature sensor might also be faulty, failing to detect the actual cabin temperature, leading the computer to adjust the airflow incorrectly. If the expansion valve is stuck or the thermostat fails, the switching between hot and cold air becomes chaotic. This is especially noticeable during high summer temperatures when the compressor is under heavy load, and if the fan stops, the condenser can't dissipate heat properly, blowing out more hot air. These issues require professional tools for diagnosis, such as using a pressure gauge to check for leaks. Regular maintenance, like topping up refrigerant and cleaning the filters to prevent odors, can improve the AC's overall performance and avoid such problems.