What Causes the Abnormal Noise When Turning on the AC Button?
2 Answers
When the car's air conditioning system produces abnormal noise upon turning on the AC button, the possible causes are analyzed as follows: 1. Belt Slippage: The air conditioning compressor is driven by the engine crankshaft via a belt. If the belt becomes loose, aged, severely worn, or the tensioner lacks sufficient tension, it may cause the belt to slip, resulting in abnormal noise. 2. Air Conditioning Compressor Malfunction: When the AC switch is activated, the air conditioning compressor starts operating. If the compressor is damaged, it may produce abnormal noise. 3. Foreign Objects in the Air Duct: If there are foreign objects in the air conditioning system's air duct, these objects may rotate repeatedly with the blower's airflow and collide with the air filter, causing abnormal noise.
When the AC button is turned on, there is a noise. I have encountered similar situations before, and it's usually an issue inside the switch. Sometimes, after prolonged use, the internal contacts of the switch wear out or get dirty, causing a clicking sound when turned on. It could also be the noise from the relay when it activates. The relay is like a small electromagnetic switch, and if it's about to fail, the sound may become unusually loud. Another possibility is that the compressor fails to start smoothly, causing unusual noises from the system. Don’t ignore these issues. I recommend first checking if the switch itself is loose or shows signs of aging, and replace it if necessary. If the noise is particularly harsh, it’s best to have a professional technician inspect it with diagnostic tools. Ignoring it for too long may lead to AC system failure, making driving in hot weather unbearable.
