What are the reasons for no air flow when the air conditioning is heating?
2 Answers
Reasons for no air flow when the air conditioning is heating: 1. Blower motor failure: Possible causes of blower motor failure include overheating damage to internal coils or capacitor damage. Turn the car air conditioning fan speed and air volume to the maximum and listen to the sound of the blower motor to determine if there is a fault; 2. Air filter failure: Outside air passes through the air filter before entering the car, and it also absorbs many airborne particles, making it prone to clogging. The air filter can be removed for inspection; 3. Issues with the car air conditioning control system: The air door, control switch, or car air conditioning computer could be the cause of the fault. It is recommended to visit a repair shop for inspection and repair as soon as possible to avoid future troubles.
When I used to repair cars, I often encountered issues with the heater not blowing air. In most cases, the problem was a faulty blower motor, which is responsible for pushing warm air from the engine heater into the cabin. If the motor is aged or heavily clogged with dust, the fan won't spin. A blown fuse is another common issue—check the fuse box to see if the AC-related fuse is blackened. With a faulty relay, you might hear a clicking sound but no air comes out. If the temperature sensor is inaccurate, the system might shut off the blower thinking it's overheating. A clogged air filter can also reduce airflow, making it seem like there's no air coming out. My usual approach is to first check if the filter is clean and try replacing it; then use a multimeter to test the motor's voltage. If the issue persists, it's best to take it to a professional shop to check the control module. For prevention, cleaning the AC system before winter each year can significantly reduce the chances of failure.
