Has anyone ever had this problem or does anyone know how to fix it?

In my 1991 f-150 when I put it on floor heat it does not blow on the floor it just stays on defrost. if i put it on vent it goes to vent but I cant get it to blow on floor.
I need the floor option to warm my feet this winter. any help would be greatly appreciated.

 

if im not mistaken, the heater vents have something like a vacuum hose and vacuum controlled switches in the air ducts underneath the dashboard.... you might have a vacuum hose that is leaking or disconnected.... you better watch, because i had a ford mustang that had a problem like that..... i found out that the previous owner put clip on air fresheners in the heat vents, and one of the air fresheners had fell down inside the heater duct system (it wasn't very easy trying to get it out either!)

 

oh yea, i just remembered, you have a 91 f150..... since its that body style, i dont think its all vacuum controlled.... sorry for the misunderstanding.... you might wanna try to go to a junkyard and find another heater selector (switch).... that might be your problem!

 

the cable under the dash make sure its in the right position give it a pull or a push to adjust it or take it off and manualy set it and see if it changes if not one of the levers in the box is broken

 

Ok I will check them few things.
Thanks