My air only blows through the defrost and floor vents 1998 Ford F-150

SOURCE: 2001durango vent only blows air through face vent and defroster.

the vent door is broke in the heater control box under dash

SOURCE: Air not coming out of vents 99 durango

theres a sensor to open the right vent for the ac try flipping
the switch to heat to ac if this doesnt work than you will have to take to a dodge dealership

SOURCE: ac will not blow thru ac vents, only thru defrost vents.

if vent doors are operated by vacuum check for loose or broken vacuum hoses in the engine compartment , or check the fuse box for any ac/heat fuses if it is a electricaly controoled system

SOURCE: Air not blowing out of the vents of my 2003 Dodge Durango

From what I hear it is a vacuum line issue. Mine is doing the exact same thing. So, I am going to get a diagram and try checking the vacuum lines to see if any are loose or tore

I go under the dash and feel the air flowing out the floor and it is coming out of the defrost, also. I noticed under the drivers side today that air is flowing and there seems to be a gap in between a part under there. There was some material stuff I saw around the edge of it that sticky brown stuff and it sometimes before came out my vents all the time. Anyways, not sure if my air is just not sealed good to blow out the vents but it is something that happened not long ago and we've not done anything under our dash area.

SOURCE: 2003 dodge durango front AC vents not working

had this trouble in a dakota it was a blend door in the heater unit. had to remove entire dash to repair