A recent problem on my 1999 S-10 blazer. When I set the control for floor heat, all the air blows out the defroster port. It's either that or the dash vent exhausts. Never to the floor. Does anyone know where the routing is actually done? I took apart a good amount of my dash but the only controls I saw move were for other functions.I'm sure there's another vacuum dashpot somewhere, but I cant see it.