a/c heat controls vacume ?

[roy c]

when i slide the heater a/c controls to any position , wxample defrost or heat or a/c the air blows out of all the vents . I was told the hose leading to the vacume ball on the fire wall was off or defective i checked the hose looked fine. is ther something i overlooked thank you all roy

 

[J Knight]

IIRC There is a inline check valve(one way valve) between the motor and the ball to keep the vacuum from bleeding off. It may be bad, or backwards or not there at all. Maybe the dash selecter valve is bad or leaking vacuum. Just a guess.

 

[smurph20]

Just because the hose looks good doesnt mean it is. Plug one ends of it and draw vacum on it with a guage and see if it holds. If anything just replace the hose and see if it works then.