What are the reasons for being unable to turn off the car's air recirculation?
2 Answers
There are several reasons why the car's air recirculation cannot be turned off, including damage to the recirculation air switch or a malfunction in the car's air conditioning control circuit. Damaged recirculation air switch: It is necessary to inspect the vehicle's onboard computer or check the recirculation air fuse and carry out repairs. If the car's recirculation air switch is manually adjusted, it might be due to the detachment of the control panel's rear hook. In this case, a mechanic should be consulted to remove the control panel and reattach the hook. Damaged car air conditioning control circuit: If the control circuit is damaged, the recirculation cannot be operated via the switch, and the vehicle should be taken to a service station for inspection. How to activate air recirculation: The air conditioning defaults to external air circulation. Pressing button "4" activates the air recirculation mode. Enabling this mode helps quickly lower the interior temperature and prevents outside air and odors from entering the vehicle. The LED light on the button indicates whether the mode is active. Pressing button "4" again deactivates the recirculation mode.
I encountered this issue a few months ago—the recirculation mode in my car wouldn't turn off. The cause could be a physically stuck control button or internal contact oxidation leading to poor connectivity, resulting in no feedback when pressed. In some vehicles, the air ventilation system's flap valve gets jammed, possibly due to excessive dust buildup, mechanical wear, or blockage by debris, directly preventing the recirculation mode from switching. Another common scenario is an electrical fault, such as a blown fuse—typically located in the engine bay or dashboard fuse box—which can cause the entire system to malfunction when it burns out. During one repair, I found a burnt-out relay that disrupted current flow. In advanced models, a software bug in the electronic control module might force recirculation mode, especially when it erroneously locks the mode upon detecting poor external air quality. For prevention, regular cleaning of AC intakes and replacing filters can reduce mechanical issues. If DIY isn't feasible, it's best to have a professional technician inspect the entire system.
