I have a 69 F100 with factory air. I never could get any heat in the cab. I looked at the cables, and everything seems to work fine. So, I looked at the heater core, and it gets very hot. I took the heater/ac box out and took it apart to check all the doors/flaps to make sure they are working, and it appears they are. The way the box is made, the blower is towards the drivers side and the core (of course) is on the passenger side. It looks as if when you flip the selector to heat, it opens a small door to the right of the core and the fan pulls heat through it and out into the cab. But when I open the door, it hits the side of the heater core and only allows that door to open about an inch and a half. Also, with the box installed, there is a big rubber sleave that slips up on the right side of the box from the kick panel. There is nothing there to shut air off from coming through it from the cowl. Is this correct? I think that maybe when the heat is on, air is coming through the sleave from outside and cooling everthing down. But, when sitting still where air isn't forced through the cowl, I still don't get any heat. I'm not sure how this is supposed to work. The truck came with air, but I think it's been replaced because the heater core I have installed (and the only one that will fit) is from a 69-73 E100 van. I don't have a shop manual and I have to get this fixed for work. Does anyone have a diagram that they could email to me without too much trouble? Anyone ever had one of these apart? I've only had non-air trucks. PLEASE HELP! Thanks!

 

The door needs to open all the way up that is what is restricting the air flow i think.Why can you not get the right heater core for your truck? I havent ever had that problem im guessing that the heater core might be your problem if its not for your truck it might be the reason that your door will not open up all the way i know that that door has to be open all the way for you to get heat i have mine taken all a part right now also becaues of that door mine wouldnt open either mine was a cable problem and im gonna fix it tomorrow.I really dont have a diagram of the heater box but maybe this will help.


Jeff

 

What does your core look like? Mine has the two connections going straight down form the bottom, and the pipes are about 2-3 inches long. The one they had at advance had the connections going out the bottom, but then going straight to the side and the pipes were about 3-4 times longer. No way it would work with my truck.

 

Hey sorry it took me so long to get back to ya.My heater core has the pipes that come out the bottom and make a 90degree turn and are about five or six inches long and go right throught the fire wall the door that you talked about dosent even get close to my heater core so we must have very different units but i still think that the door needs to open all the way up for enough air to get through to heat your truck sorry that i can help anymore than that let me know if you get it fixed i would be courious to know.


Thanks Jeff

 

I see. You've got the one that Advance tried to sell me. According to their books, that's for the non-air conditioning box. Mine has factory air. I think I figured out why the door is hitting. On my old core, the pipes are both bent slightly towards the drivers side. The new one that I ordered has straight pipes. I think that will allow me to slide the core over just enough to clear the door. I'll keep you posted, and thanks for your help. Also, is the heater hose with the control valve go to the water pump or the engine on your truck? I can't remember how mind came off. Another guy on my other post said that his hose with the valve goes to the water pump. Thanks.

 

Well honestly i cant remember which one it goes in myself but im not sure it really matters to much the idea is to be able to restrict to flow of coolant to the heater core so it will cool down and either hose you put it in when you close the valve it will stop the flow of coolant i have replaced heater hoses several times and im not sure if i have been putting the valve in the same hose or not and i have never noticed and change at all.



Jeff