What Causes the Abnormal Noise When Turning on the AC Button?

[ZacharyLee]

Here are the specific reasons for the abnormal noise when turning on the AC button in a car: 1. Contaminated electromagnetic clutch: Due to the electromagnetic clutch being located relatively close to the ground, prolonged driving can cause it to accumulate dirt or mud, leading to bearing damage and resulting in abnormal noise. 2. Loose drive belt: The car's air conditioning compressor places high demands on the electromagnetic clutch during operation. A loose drive belt increases the load on the electromagnetic clutch, making it prone to damage and, in severe cases, causing the compressor to burn out. 3. Repeated engagement of the electromagnetic clutch: Frequent engagement of the electromagnetic clutch can lead to insufficient power generation from the alternator, causing the compressor to operate with inadequate voltage and resulting in abnormal noise. 4. Lack of lubricating oil: Insufficient lubricating oil inside the compressor. After prolonged use, it's necessary to add an appropriate amount of lubricating oil to avoid abnormal noise or failure due to friction.