Why is there no air coming out from the windshield defroster vent?
2 Answers
The angle adjustment button for the air vents on the vehicle's air conditioning control panel is malfunctioning, preventing the air flow from being redirected; the pipelines of the vehicle's heating system are clogged and need to be cleaned at an auto detailing or car wash shop. Below is relevant information: Air vent adjustment: There are five adjustment modes. The first is the foot mode, the second is the foot and face mode. The third is the face mode. The fourth is the windshield and foot mode. The fifth is the independent air flow mode, which can be switched via buttons or knobs according to different usage environments. Notes: The air conditioning system must have the vehicle's AC switch turned on for operation, whereas the heating system does not require this. When using the air conditioning, the vehicle's internal circulation should be activated, switching to external circulation every half hour. For the heating system, external circulation can be used without the need for frequent switching to internal circulation.
A few days ago, I encountered this issue while driving—there was no airflow from the windshield defroster vents, which was really frustrating during heavy fog. My first thought was that the AC mode was set wrong—the defrost mode should activate the fan, but the fan button wasn’t responding. I then checked the AC switch and confirmed it was on the defrost setting. If everything else seemed fine, it might have been a blown fuse for the fan, which can be replaced using a car toolkit. Another common cause is blocked air ducts, especially if the car has been parked for a long time—leaves or debris can clog the vents, requiring cleaning. The worst-case scenario is a faulty fan motor. Later, when I took it to the shop, I found out it was due to poor wiring contact, and the mechanic said voltage fluctuations often cause this. A malfunctioning defroster is extremely dangerous as it obscures visibility. I recommend immediately turning on hazard lights and pulling over—don’t try to fix it yourself to save money. Professional repair is the way to go—safety always comes first.