Why does the car air conditioning not cool at idle but cools when driving?

[VonFinley]

Common reasons why the air conditioning does not cool at idle but cools when driving: 1. Air conditioning compressor failure: The pressure between the air conditioning compressor and the expansion valve cannot reach 150Kpa to 200Kpa, preventing the refrigerant inside the system from circulating normally, causing the air conditioning not to cool at idle. 2. Expansion valve damage: The expansion valve cannot form high pressure, less than 150Kpa, so the evaporator behind it cannot cool down, leading to no cooling at idle. 3. Loose or broken air conditioning belt: If the drive belt is too loose, it will slip, accelerating wear and failing to transmit power, resulting in insufficient power at idle, thus not cooling enough. 4. Dirty condenser: The condenser is used for heat exchange. If the surface is too dirty or covered with too much dust, it will not cool, naturally causing the air conditioning not to cool. 5. Radiator blockage: The external cooling system will not dissipate heat well, leading to poor heat dissipation at idle, causing no cooling at idle. 6. Blower fan failure: There is abnormal noise inside, or the motor operates poorly, resulting in insufficient airflow.