so my 98 z34 monte carlo only blows the air below my feet and threw the defrosters no matter what setting i put it on! the A/C still works heater everything but it only blows thew the defroster and at my feet, how can i fix this i'm sure its just someting broken behind the dial but i'm not sure!

 

this happened on my parents suburban, but it was with the rear a/c that could be controlled from the front. when you put it on rear control, it was always on high, no matter what. it turns out something inside the switch had broken... bought a new switch and it went right to work.

 

Had this problem on my 02 monte after seeing that I was getting no vacuum at the controls I pulled my dash apart to find that it was a broken vacuum line under my hood by the battery