What Causes a Car Air Conditioner to Keep Cooling Without Stopping?
3 Answers
There are several reasons why a car air conditioner compressor does not shut off: 1. Temperature setting too low: The car AC temperature is set too low, causing the compressor to run continuously. A faulty temperature sensor can also lead to continuous compressor operation. 2. Damaged thermostat: A broken thermostat on the indoor unit's control board prevents the compressor from stopping. Refrigerant leakage in the AC system results in insufficient cooling, causing the compressor to keep running. Check if the temperature sensing tube connected to the thermostat has come loose; if so, reattach it to its original position. 3. Temperature control switch: When the temperature control switch detects high ambient temperatures, the AC compressor will operate for extended periods. This abnormal condition requires replacement of the temperature control switch.
I've driven many cars and encountered issues where the air conditioning keeps cooling without stopping. This is usually due to a faulty temperature sensor or a stuck compressor clutch, which prevents the system from detecting the cabin temperature and stopping automatically. The sensor is located behind the dashboard and may accumulate dust or fail over time, causing the system to misjudge and keep running. The compressor clutch is in the engine compartment, and if it rusts or gets damaged, it won't stop turning. For a simple self-check, feel the AC vents while driving—if they're icy cold and producing white mist, it's a serious problem. Don't underestimate it; fuel consumption will increase significantly, and over time, the battery will wear out faster. Driving in summer becomes particularly dangerous as it can easily distract you. It's recommended to visit a professional repair shop promptly for diagnosis and repair using specialized tools.
As someone who often works on cars myself, I think there are several common reasons why the air conditioning doesn't cycle off: First, the thermostat module is faulty, meaning the component responsible for regulating temperature is malfunctioning; second, there's a refrigerant leak or abnormal pressure, as insufficient refrigerant will cause the compressor to keep running to compensate; third, a relay or fuse in the circuit box is burned out, leading to poor control. You can try checking yourself—after turning off the car, open the hood and inspect the fuse box at the position marked with the air conditioning icon. If the fuse is blown, try replacing it with a new one. You can also use a multimeter to measure the resistance of the control panel for a preliminary diagnosis. Avoid randomly repairing the compressor or adding refrigerant, as this can easily damage the system. Delaying repairs for such issues can lead to higher costs later and may even shorten the air conditioning's lifespan.
