I'm having a problem with my heater controls. When placing the switch to any position, the air only comes out of the defrost. After a while and tinkering with the switch back and forth ever so slightly, the air ducts will finally come out of the vents and floor. I've traced all the vacuum lines out except for the red one. I don't know where this one goes. Can anyone point me in the direction to look, and also does any one know where I can get the vacuum lines? While troubleshooting this problem I cut the lines off the plug and individually put them back on the valve on the back of the control head. I think my problem lies in the valve itself. When I place the control to vent we'll say, I can here a hissing and if I squeeze the valve on the left corner a little bit, the hissing stops and the doors will open and close as normal.

 

Defrost is the default for a vac leak. From your description, I'd guess the problem is the switch. Check the following link for more info:

https://www.thirdgen.org/forums/inte...ht=control+vac

JamesC