my 2000 ford ranger is only blowing air out of defrost and floor on any setting. I believe it has a vaccum leak somwhere, does anyone know where the vaccum line that controls the vents would be and how i can fix this? thanks

on the passenger side behind the windshield washer fluid bottle there is a line from the blower motor to a vacumme ball under the air cleaner box. mine had touched something hot and melted a hole. check the lines from this vacumme ball. if not, it could be the blend door mechenisim behind the glove box. they had problems with these getting stuck.