When I turn on the heater/ac or defroster I can hear the fan running but no air is blowing out of the vents
A mouse nest maybe?
[b]I Can’t Help You, Except By Making A Wild Educated Guess![/b]
However, by stating the requisite Year, Miles, and what kind of HVAC controls (manual or climate control, etc.)are in your vehicle, maybe a Ford Expert or Explorer owner can help you. Some problems are make/model/year/option specific.
The most common malfunction is the blend door motor not working, keeping the door closed, hence no airflow.
I thought that the blend door on those selected between heated and cooled air, such that no matter where it stopped, you would still get air flow (the only question being will it be hot, warm, or cold).
By no air out of the vents, do you mean out of the dash vents? Have you checked for air flow out of the floor and defrost vents? Do you also have no airflow in the AC MAX setting? (If you do get airflow in this setting, then your fresh air door is stuck closed. It’s under the hood near the windshield on the right side.)
No year posted nor system type ( ie. ATC or manual ), So everything here is a flat out guess.