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73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: idahok1085 on October 10, 2008, 12:18:25 am

Title: 85 K10 Heater problem
Post by: idahok1085 on October 10, 2008, 12:18:25 am
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  ;D
Title: Re: 85 K10 Heater problem
Post by: Captkaos on October 10, 2008, 12:21:17 am
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?
Title: Re: 85 K10 Heater problem
Post by: idahok1085 on October 10, 2008, 12:34:05 am
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......
Title: Re: 85 K10 Heater problem
Post by: Captkaos on October 10, 2008, 12:35:33 am
Are the hoses hooked up to the heater core on the outside of the firewall?
Title: Re: 85 K10 Heater problem
Post by: idahok1085 on October 10, 2008, 12:39:25 am
Yes....... Not sure about Vacuum tho.......
Title: Re: 85 K10 Heater problem
Post by: justinm on October 11, 2008, 09:53:54 pm
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