i have a 95 f150 that I jerked most of the vacuum out when I took the smog pump stuff off, I can only get my vent to blow on the defroster setting even if I change the selector around, does anyone know how the switch gets vacuum to it from the engine? I wasnt sure how it came through the firewall, so that I could make sure I had vacuum. any ideas???

 

Should be one of those small black plastic/nylon hoses coming through the firewall.

I was thinking it was tied into the intake plenum's vacuum manifold - but it might be coming off one of the feeds from the vacuum reservoir canister.

This black hose supplies the selector in the cab. From there, lines go out to the three vacuum motors - the floor/defrost, floor/panel, and the recirc.

 

so basically, i just need to find the vacuum line that goes throught the firewall and make sure it has a vacuum line hooked up to the intake?

 

Yes, the vacuum line that goes through the firewall needs to be hooked to the intake manifold vacuum tee. Defrost is the default setting when the vacuum isn't hooked up so that no matter what you can still defrost the windshield.