my defroster dose not work air blows out from bottom but not vents on dash...

[RaymondFrausto]

...or defroster? I have a 77 cutlass supreme and my defroster don't work air only blows from bottom vents not vents on dash or defroster what can this be? How can I fix it or how much will it cost
So it can be a vacuum leak... cause none of the vents work but the floor ones. How much could thus cost if I take it to a shop?

 

[Paul]

"It Defaults to Floor Vents" Heater Directional Vent Doors, Control Cable or Vacuum line Broken.

 

[kmjc8131991]

that's a vacuum leak its not easy to find either sorry thats all i know..... had that with the t bird and found it over two days and jb welded it hahaha