What Causes the Car Air Conditioner to Buzz Loudly with Weak Airflow When Turned to Maximum?
2 Answers
When the car air conditioner is turned to maximum and produces a buzzing sound with weak airflow, the following reasons may be the cause: 1. Air conditioner compressor failure: If the air conditioner compressor malfunctions, it can lead to abnormal noises or poor cooling/heating performance in the car air conditioner. This situation is relatively complex, and it is recommended to visit a repair shop or 4S store for a detailed inspection by professionals. 2. Air conditioner belt slipping or wear: It is advisable to directly replace it with a new belt. 3. Blockage in the air conditioner pipelines: If there is a blockage in the pipelines of the air conditioning system, the internal gas cannot circulate normally, resulting in abnormal noises. In this case, the entire pipeline system of the car air conditioner should be inspected and cleaned.
As someone who frequently tinkers with cars, I think when the AC is turned up to maximum and it's buzzing loudly with weak airflow, it's most likely due to a faulty blower motor bearing. The same thing happened to my car last time—it buzzed like a fly, and even at the fourth fan speed, the airflow was weaker than others' at the first speed. After taking it apart, I found the bearing was both dry and rusty, making it extremely hard to rotate. Another possibility is that the blower fan blades have picked up leaves or paper scraps, causing them to wobble and make strange noises at high speeds. Of course, we can’t overlook the cabin air filter—if it hasn’t been replaced in three years, dust buildup can block it like a wall, and no matter how hard the blower works, it won’t pull in air. Lastly, check the resistor module—if the part controlling the fan speed is faulty, it may struggle at higher speeds. Ignoring this issue for too long could burn out the motor, so it’s best to address it promptly.
