What to Do When Car AC Makes Loud Buzzing Noise with Weak Airflow at Maximum Setting?
2 Answers
Adjust the fan speed setting, check the air outlet mode, and inspect whether the air vents or ducts are blocked. Below is relevant information about car air conditioning systems: 1. AC Composition: Modern air conditioning systems consist of refrigeration systems, heating systems, ventilation and air purification devices, and control systems. 2. Working Principle: Automatic AC functions include automatic adjustment of interior temperature and humidity, automatic control of air recirculation and supply modes, as well as operation mode and air exchange volume control. The electronic control unit will automatically operate the AC system based on settings made by the driver or passengers via buttons on the AC display control panel, and timely adjust air supply temperature and speed according to signals from various sensors to maintain optimal in-vehicle air conditions.
I encountered this situation last week when driving on the highway—the AC suddenly started buzzing loudly but the airflow was very weak. After checking, it turned out to be mainly two issues: either the cabin air filter was too dirty and blocked the airflow, or there was something like leaves stuck in the blower motor. When I opened up my car, the filter was completely covered with poplar fluff, making it impossible for air to pass through. Additionally, half a plastic bag was tangled in the fan blades, causing a loud buzzing noise when spinning. After replacing the filter and cleaning the fan, it immediately became quiet, and the airflow returned to normal. I suggest you first check the condition of the filter behind the glove box—it tends to get clogged if not replaced every six months. Replacing it yourself is quite simple, with plenty of tutorials available online. If it still makes noise after cleaning, you might need to dismantle the dashboard to inspect the blower motor bearings, which would require a professional mechanic.
