What Causes No Airflow from the Rear Air Conditioning in a Car?
2 Answers
Reasons for no airflow from the rear air conditioning: 1. Air leakage at the connection between the evaporator housing and the air duct: If there is air leakage at the connection between the evaporator housing and the air duct, the cold air that should be released from the rear air conditioning vents will continuously escape from the leakage point, resulting in reduced airflow from the rear vents. 2. Issues with the cabin air filter: The cabin air filter is located at the intake of the blower. All cold or warm air blown out by the car's air conditioning system must pass through the cabin air filter. However, the cabin air filter is prone to accumulating dirt. If the owner does not replace it in time, the filter can become clogged with dust, leaves, dead insects, or even rodent remains. These obstructions naturally reduce the airflow through the filter, leading to decreased airflow from the rear air conditioning vents. 3. Poor sealing of the auxiliary air duct: The rear air conditioning vents are connected to the blower via an auxiliary air duct. If the sealing of this duct deteriorates, air leakage occurs, reducing the airflow from the rear vents.
The rear air conditioning has no airflow, which I've encountered while driving, and there could be several reasons. The most common issue is the rear vent settings. Many cars have independent switches on the rear panel, which might have been accidentally turned off by kids, or the airflow distribution setting is incorrect—maybe the rear priority wasn’t selected when adjusting the airflow on the AC panel. Another frequent cause is a clogged filter, especially after prolonged use when dust and debris accumulate in the ducts, blocking the airflow. It’s essential to replace the filter regularly. A faulty fan is another factor—the small motor for the rear AC may have aged or gotten damp, causing it to stop working. A blown fuse is also possible; check the corresponding section in the fuse box for the rear AC. Air leaks or cracks in the ducts are common too, often due to aging seals causing air loss. These issues not only affect comfort but can also make rear passengers, especially kids, uncomfortably hot during summer road trips. I recommend first checking the settings and the filter yourself. If that doesn’t solve the problem, take it to a professional repair shop—safety comes first.
