85 K10 Heater problem

[idahok1085]

Hey guys, New here. I just picked up a 85 K10 and my Heater isent working here is what is going on:

The fan turns on all settings Low-High, sounds stroung ect. The part that moves from Vent/Def/floor/AC ect ect moves I looked behind there and it appers to me that ALL vac. lines are hooked up, none broken that I can see.  It dose blow out the floor all the time dosent matter what setting I have it on. Also if I turn the sel. all the way to OFF on there it turns it OFF. It just wont turn to Vent or Def. Dose anyone have a Vacuum Diagram of under the hood? Also it has a 350 Swap done to it. Aftermarket Holly carb and intake. Also the HEAT is not hot its cold. Im thinking bad T-stat but I will look into that after I figger out why its not blowing out def. and vents. Any help would be a life saver!! Thanks guys!! I hope I get more help on this site than the others haha 

[Captkaos]

If you aren't getting hot air to the floor are you getting hot water to the heater core?  Are the lines hooked up?  Is this and AC truck or non-AC?

[idahok1085]

IT has A/C but I dont have the belt on becuase its almost winter here and I need the heat lol. Everything looks hooked up inside the cab......

[Captkaos]

Are the hoses hooked up to the heater core on the outside of the firewall?

[idahok1085]

Yes....... Not sure about Vacuum tho.......

[justinm]

your not getting vacum from the engine to the heater control. The hose comes out of the firewall near the heater housing. Make sure you hook it to manifold vacum