air conditioner vent problem

I have just recently purchased a 1988 chevy silverado, 5.7 , 4x4 with air. When changing from air to defrost to floor it only blows on the floor. Anyone have any ideas as to what the problem might be.

Sounds like the gate inside isn't moving. The best way to figure it out is just to take off the glove box and see if something is blocking it. My 86 used to do what you said and I took it apart and fooled with it and now it works so hopefully you will get lucky too.

Sometimes a wire or a part of the linkage gets caught up or falls apart like abaird said. Have a boo, under your dash you may be able to see where the linkage is getting caught up...

I took the glove box out but didn't go any further. Will I have to take the entire dash apart to figure this one out. I have also discoverd a distinct antifreeze smell. There are no obvious leaks, and the truck isn't overheating. The hose that goes from the intake (at rear of block) to the heater core appearse to just about be desinigraded. could this be the source of the smell, or should i be more concerned. The floor board on the passenger side isn't wet at all so I don't think the core is bad.

that hose you mentioned sounds like a good place to start