Why does the car air conditioner not cool when parked but cools when running?
2 Answers
The reasons why the car air conditioner does not cool when parked but cools when running are: 1. Lack of Freon; 2. Compressor pressure loss, directly leading to severely low pressure at idle; 3. The air conditioner cooling fan does not rotate, resulting in poor heat dissipation when parked, causing the pressure to be severely high, and the high-pressure sensor forces the compressor to stop working; 4. The expansion valve nozzle is too large, causing excessively high low pressure at idle, which greatly reduces the air conditioning effect when the low pressure is high. The functions of the car air conditioner are: 1. To adjust and control the temperature, humidity, air cleanliness, and air flow inside the compartment to an optimal state; 2. To provide a comfortable riding environment for passengers and reduce travel fatigue; 3. To create good working conditions for the driver and ensure driving safety.
I found that when the car is stationary, the air blown by the AC is not cool, but once the car starts moving, it becomes very cold. This is usually caused by the cooling fan not working when the car is parked. The fan is responsible for dissipating heat from the condenser. If it's broken or the switch is faulty, the AC won't cool properly when parked because there's no heat dissipation. When driving, the increased airflow replaces the fan's role in cooling the system, improving the effect. It's recommended to check the operation of the electric fan, see if the fuse is blown or if the wiring is loose. Also, consider whether the refrigerant is insufficient or if the compressor is aging, leading to weaker performance at low speeds and improvement at high speeds. Regularly cleaning dust from the condenser and radiator surfaces is crucial, as blockages can worsen the problem. After experiencing a similar situation, I always get a maintenance check before summer to avoid sudden breakdowns in hot weather. Timely repairs ensure driving comfort and safety—don’t delay, as small issues can turn into major repairs.
