Front Window Blower (demistor) problem

[VTSSDUDE]

Hi, I have a VS ute that when you select the air vent to front window no air comes out of the vents, but there is air coming out of the side of the centre heater control box and there isva hissing sound from the control switch area. I have replaced the switch control part. I still have this problem, but the switch was second hand laying around my back yard so it fould be faulty too. Is there any other areas I should be looking at?
Thanks in advance.

[88GreenVN]

You have a vac hose off some place. Check all vac hoses unde the dash to the top servo.

[Phoenix21]

there is one hose that comes off pritty often and thats in the drivers foot well and it next to the white heater switch