Why does the car air conditioner not cool when the car is not running?
2 Answers
Reasons why the car air conditioner does not cool when the car is not running: 1. Insufficient battery voltage: The car air conditioner requires electricity. If the voltage is insufficient, it will not cool. When accelerating, the engine generates electricity to provide higher voltage to the battery, allowing the car air conditioner to cool normally. 2. Compressor operation status: If the compressor belt slips, it will affect power transmission, resulting in insufficient pressure at low speeds; internal components of the compressor may be damaged, causing noise, and internal wear may prevent effective compression; if the compressor clutch slips, it will also lead to insufficient compression pressure. 3. Condenser and fan status: If the condenser radiator is severely blocked, the condenser's efficiency will decrease at low speeds; check if the condenser fan is faulty—if there is noise or poor motor operation, it will affect insufficient airflow at low speeds. 4. Refrigerant level inspection: Observe the refrigerant in the inspection window for excessive bubbles; check the high and low-pressure pipelines and connections for leaks—repair or replace if necessary.
I've found that car air conditioning not cooling during idle is a common annoyance, with many friends complaining about the cabin becoming as hot as a steamer when waiting at traffic lights in summer. The main reason is that the engine speed is too low to properly drive the compressor's normal operation. The compressor is the 'heart' of cooling, driven by the engine belt; at idle, insufficient RPM drastically reduces cooling efficiency. Another possibility is the cooling fan not spinning, triggering the system's overheating protection. I recommend idling the car for a few minutes after starting to let the AC warm up, which can help. If it consistently fails to cool, check whether the fan is rotating or if the refrigerant level is adequate. Addressing these minor issues promptly can spare you from suffering in extreme heat. Develop a habit of regular AC maintenance - simply topping up refrigerant or replacing fan gaskets will do.
