I'm having trouble comprehending the heater & defrost cables. There are two cables on the bottom control lever, one is for the heat/defrost flapper the other closes the flapper in front of the blower wheel. When I move the lever to defrost the cable for the defrost door barely moves. It doesn't seem enough to divert air. This is on a non A/C fresh air heater

 

To clarify my problem, the heat/defrost cable seems to not move and all the pivoting action is on the other cable. Is there a pivot point for the bottom leaver that can break? I connected everything and the lever want move all the way to defrost.

On another note why did Ford put the second door that blocks air flow from the blower or does it work in conjunction with the defrost door to direct air flow?

 

Anthony, Doesn't one control fan speeds and hot water flow. My 66 doesn't have a deluxe set, and it's toooo dark & toooo cold to go out & look now. My trucks defrost/heat is controlled by hand from the lever on the side of the box and for the most part I leave alone with it in the middle.

It has been a while since I have messed with one.



John

 

this is in a '70 deluxe fresh air box, fan speed is controlled by switch, one cable on top leaver for temp control them two cables on bottom lever for defrost/heat and air flow, it's a weird setup on the bottom lever

 

I should have taken pictures when I had it all apart yesterday. Check out Keith's pictures on this link <!-- m -->http://www.fordification.com/tech/AC-cables.htm<!-- m -->

These pics are for a A/C truck but the only difference is the top lever has two cables, the bottom lever is the same and serves the same purpose. I'm dealing with cables 3 &4 in his pics.

 

The cable may have slipped in it's clamp as mind did throwing it out of adjustment some.
If your not getting much of air flow all the lever doors foam seals may have dry rotted as most of these old classics have done now.

To fix You'll have to punch out the rivets that hold the back sheet metal cover in place.
Now where do you get replacements~~~?
I've bought first LMC heater box kit, and the main air door seal was to small, plus theirs looked more like it's was made from some home AC filter material thin foam and was not even wide enough to block air from passing around the sides of the flap levers.

Then ordered Mac's their fit much better and made from much better material but still did not fit as good as the old foam seal, I removed Shi:t so ordered DC heater box seal kit. DC and Mac's were about the same size not wide enough to stop air from passing by the sides. So I glued seal from DC to over lap the sides to widen side to closed the door side gaps.
If, I did not do this air will flow around the air door all the time. Which means hot air will inter the cab in the summer time making the cab and your feet damn hot!

orich

Then tried Mac's heater kit lhere's

 

I decided to restore the heater box because the core leaked. I bought the DC seal kit and it fits well. The box seems to function well. I never had much air flow before disassembly. When I removed the box I noticed someone had cut the cable to the air flow flap. It was shut hence the low air flow I had. Aftrr reassembling everything I've discovered this problem. The defrost lever will not move all the way to defrost. The lever pivots by the defrost side if the lever will not slid as it should to pull the cable and move the defrost flap. I will take it back apart next week and remove the defrost cable. I replicated the cut air flow cable located on the same lever.

Shouldn't the lower lever pull the defrost cable when you slid it over? This thing has a weird movement. It seems like it needs a pivot point in the middle but mine isn't anchored to anything.

I have it stuck in heat now so at least I have a heater. I get good airflow

 

I know when I replaced mine I had an issues when I reassembled everything. The doors in the heater box can catch each other if the cable are not adjusted properly. This will make it where the lever only goes half way across.

 

I had the same issue with my heater controls, turned out one of the cables was stuck and not allowing the lever to go to defrost. The reason it was stuck was the wire inside the jacket had been bent and created too much resistance. Couldn't tell by just looking at the outside, I disconnected the cables and checked how freely they moved. Seems any resistance will cause problems. Just something to check....

 

That must be my problem. The one cable I didn't replace could be the problem. I will remove both cables and see what happens.