What Causes the Belt to Squeak When the Car Air Conditioner is Turned On?
4 Answers
The reason why the car air conditioner belt squeaks when turned on may be due to insufficient tension of the compressor belt or a problem with the compressor's clutch. Below is an introduction to car air conditioners: Function: Used to adjust and control the temperature, humidity, air cleanliness, and air flow inside the car cabin to the optimal state, providing a comfortable riding environment for passengers, reducing travel fatigue, creating good working conditions for the driver, and playing an important role in ensuring safe driving as a ventilation device. Composition: Generally includes refrigeration devices, heating devices, and ventilation devices. This combined device makes full use of the limited space inside the car, with a simple structure that is easy to operate.
Every time I turn on the AC and hear that annoying squeaking sound, it's mostly caused by the drive belt. When the AC starts, the compressor pressure increases, and if the belt is loose or worn out, it slips and makes that harsh noise. I remember my car had the same issue last year—the inspection showed insufficient belt tension, plus oil and dust buildup on the surface increased friction. It gets worse in high humidity, as rain or haze can make the belt even more slippery. Get to a repair shop ASAP to adjust or replace the belt. Otherwise, it might snap, causing the AC to fail and potentially damaging other components like the alternator. During routine maintenance, just check for cracks or looseness in the belt to avoid bigger problems.
My old car had the same issue - the belt would squeal whenever the AC was turned on, which is actually quite common. Most of the time it's caused by incorrect belt tension; when it's too loose and lacks elasticity, the sudden load increase from AC activation makes it slip and create friction. I've even tried checking it myself: after turning off the engine, press the belt to check for looseness, and inspect for obvious cracks or stains on the surface. Sometimes cleaning off dirt can solve the problem, but long-term neglect will accelerate belt wear. During regular maintenance, remind your technician to check the tension to prevent minor issues from escalating. Proper AC system operation is crucial for summer driving - don't ignore problems when they arise, addressing them promptly can save you money in the long run.
This sound is usually caused by belt slippage. When the air conditioning starts, the compressor boosts pressure, increasing friction between the belt and pulley, resulting in noise. If it's a new belt, improper installation or insufficient tension may be the issue; an old, worn-out belt with weakened elasticity is more prone to problems. Ignoring it could lead to belt breakage, leaving the car stranded. It's recommended to turn off the air conditioning immediately upon hearing the noise to reduce load and drive safely to a shop for inspection. During repairs, don't just replace the belt—also check if the pulley system bearings are worn, as these can cause similar failures.
