If the mode **** is anywhere but OFF or MAX-AC, the fresh air intake door is wide open so forward vehicle movement is going to force air in. That amount of air that blows in will depend on speed. On MAX AC or OFF, the fresh air intake is closed. With the **** in the OFF position, there shouldn't be any air movement at all since the fan isn't running and the fresh air door is shut.
The blend door is something different. That is controlling air directed through the heater core to regulate temperature, not where it comes out and when.
Last edited by FireRanger; 07-21-2008 at 04:24 PM.