Only Defrost&Floor Vents

[Glayton2003]

I recently bought a 1991 GT and everything is running smoothly except I only have air coming from the defrost and floor. I have checked all of the vacuum lines in the engine bay and just want to know if there is another common place that might be leaking, or if there is something else wrong altogether.
Thanks, Gatlin

 

[ALMOST STOCK]

Have you checked to see if the cable on the temp blend door is working properly.

 

[Glayton2003]

Have you checked to see if the cable on the temp blend door is working properly.

View attachment 3693
View attachment 3694

No I have not, what is the best way to get a visual to check it? The temperature blend still works, I can get hot and cold. It just wont change from defrost and floor.

 

[ALMOST STOCK]

No I have not, what is the best way to get a visual to check it? The temperature blend still works, I can get hot and cold. It just wont change from defrost and floor.

Try checking the Blue vacuum line that goes to the vacuum motor for opening or closing the panel door, (see 1st attachment).

 

[ALMOST STOCK]

 

[RCMUSTANG]

It's the first door near the passenger side if it's only defrost and floor. Check the main vacuum line that goes from the check valve into the hvac case. Usually when you lose vacuum to the hvac it blows only to defrost and floor as It's the default position of that first door.

 

[Glayton2003]

Okay, Thank you guys I will check these suggestions out. Really appreciate the help!