97 Dodge Ram 1500. Anyone know why my heat blows to the floor vent only? Turn the selector **** and nothing changes?

 

Bad control switch, stuck doors in the heater box, broken vacuum lines. Need to have a look under the dash, and see whats up.

 

I do know that loss of vacuum from either one of the lines going to the intake vacuum source will result in defrost only. Sounds like a blend door stuck closed.

 

Ah-HA! Glad I saw that, after some engine bay work I found I only have defrost and a loud hissing coming from the engine bay... You just confirmed my suspicion of a cracked vacuum line! THANKS! Now I just have to find it, ugh

I also second your "Blend door stuck" opinion too. I read one guy said he had a similar problem, but after changing the selector back and forth a few times each time he got in the truck, it broke free after a few days. Worth a shot, hell of a lot easier than pullin the dash!