vacuum hose for vents and defroster
 

i got a non ac cab but done cut the firewall for this have all the stuff from a burb for under dash etc all i want is the heat and vents and defroster to work all the lines are hooked up to actuators the main source from engine the line was melted can i just hook up to a vacuum source from intake to the source line then to ac controller thanks
Posted via Mobile Device

Re: vacuum hose for vents and defroster
 

The ones I've seen attach to a vacuume fitting on the top of the intake behind the carb. Somtimes the one fitting in the intake has 2 or 3 different spots for different vac. functions or the main line has a "T" in it. There should be a vacuum line supplying vac to the controler, some trucks also had a round vacuum resivour. I think I've seen them mounted either above the heater core on the outside of the cab, or over by the fuse box on the outside of the cab.

Re: vacuum hose for vents and defroster
 

In short, yes.
There is supposed to be a vacuum res (ball), but mine broke, so running off straight manifold vacuum now. There is what appears to be a check valve? cut into the factory line. function would have to be investigated.

Re: vacuum hose for vents and defroster
 

These might help:

http://s3d4.turboimagehost.com/t1/16274737_57433492.JPG

http://s3d4.turboimagehost.com/t1/16274739_57433537.JPG


The check valve is to prevent loss of vacuum (used to position the HVAC dampers) during times of low intake manifold pressure - i.e. at WOT.