For some reason my vents do not change from floor heat. The screen on the dash changes when I hit it but it keeps blowing floor heat, it may blow a little defrost but mostly on the floor. Is there a motor that changes the airflow? What could go wrong? Any help would be great. thanks

 

There is a blend door behind the glove compartment. Not sure if its electrical or works off vacum. Feel or look back there and see if you can hear a hissing or loose hose while the truck is running. If not then you might have an electrical blend door.

 

There is also an electric motor that is probably either bad or one of the metal arms has come loose. It is either behind the glove box or under the dash just above and towards the middle a bit of the gas pedal. I can't remember which that year.

 

Do you have to take the dash board off to fix it?

 

No you can fix it from underneath.