What Causes the Low Airflow of Car Air Conditioning Heating?
3 Answers
The reasons for the low airflow of car air conditioning heating are: 1. The blower power is insufficient or the ventilation ducts are blocked; 2. The air conditioning evaporator and heater radiator are clogged with impurities; 3. The air filter element in the heating duct is too dirty. The method to turn on the heating in a car air conditioning system is: 1. After starting the vehicle, turn off the AC button; 2. Wait for the water temperature to rise to the normal value, then turn on the air conditioning heating. Car air conditioning, also known as the car air conditioning system, is used to adjust and control the temperature, humidity, air cleanliness, and airflow inside the car cabin to an optimal state. Its functions are: 1. To provide a comfortable riding environment for passengers and reduce travel fatigue; 2. To create good working conditions for the driver.
My old car also had the issue of weak airflow from the heater. When I opened it up, I found the cabin air filter completely clogged with willow catkins and dust. Later, a car wash attendant told me that the blower motor had accumulated thick dust, making the blades unable to rotate. Another time, the resistor was faulty, and only the lowest fan speed worked. Honestly, this is what I fear most when driving in winter, especially on long trips—having to rely on the heater to defog the windshield. Now, before every winter, I remove the glove compartment myself to replace the filter, and a roadside shop charges just around a hundred bucks to replace the resistor. Never wait until you need the heater to discover the problem.
I've encountered this situation quite often while repairing cars in my hometown. Most of the time, it's either a clogged cabin air filter or a faulty blower motor. The filter is like a mask - when it's blocked, of course it can't breathe properly. Once I saw a car owner spraying perfume into the AC vents, which ended up making the fan wheel sticky and stuck. Nowadays repair shops use diagnostic tools to check the air door actuator. Sometimes the blend door gets stuck in the defrost position. My personal suggestion is to first check the filter location yourself - in most cars it's behind the glove box on the passenger side. If changing it doesn't help, then you'll need to test the blower motor resistor. I remember one time fixing this for a customer at -20°C, my hands were so cold I couldn't even hold the wrench. Better to address it early and save yourself the trouble.
