heater and vent controls

[68f100ranger]

i searched but didnt find anything closely related to what i was wanting to do. i need to rebuild my heater controls, the heater valve needs to be replaced and i believe that will fix that problem but the defroster cable hardly moves. now i was wondering how hard is it to remove the whole assembaly with cables so i can look at what i have to deal with. if the defroster cable isnt frozen what else could it be, and what does it take to fix said problem? thanks.

[Redcap]

When my cables bound up, I removed and let them submerge for a day or two in solvent, then hosed them down heavily in JB80. They work fine now.

The slider-type control assembly is pretty easy to remove.

[jor]

Also, if the cables are not adjusted properly on the slider mechanism, they will bind up. As long as you're going to be in there anyhow, might as well do as 68 suggests and get everything clean and shiny. I'm betting it will then work fine.

My slider mechanism on my 68 was typical with a lot of the black paint gone or scratched up. I removed it all and it looks great.
jor

[68f100ranger]

well after basically having to drive with my head out the window because the windows wouldn't defrost the other day when it was really rainy, i have decided to just rebuild the whole heater box assembly. now where is a good source for a heater core and seals? i have the lmc catalog but i have been hearing that they are overpriced or part fitment is questionable. who else is suggested for parts? also how hard is it to remove the heater box and rebuild it? what all is involved removing and refurbishing the heater box? thanks for any input.

[Jake11]

Most parts houses can get the heater core. 4seasons used to be pretty
good stuff. The box comes out pretty easy. It's fairly easy job.
Penetrating oil on the cables usually frees them up.

[fordman]

i just pulled a working box and cables tonight from a 70 without factory air. fan works heater core doesn't leak all cables work fine.

[Whoaaanelly]

I totally rebuilt my heater box recently and I bought the heater core from NPD in North Carolina at the same time I was buying other things. I used LMC for a couple items in the past, but NPD has a greater selection and pricing, so I've sort of stayed with them through the past few months.

As for the heater rebuild, I have a 67 with pull cables, so they're pretty easy to lube up, which I did with graphite oil. I also rebuilt all the flaps in the box too, which were all rusted up and the foam was falling off. Blasted, painted, and refoamed - they work like new. It's going back in this weekend hopefully.

[68f100ranger]

Alright, so i have officially decided to rebuild the heater box. how hard of a job and what parts are required when rebuilding the box completely? i have a feeling that the flaper doors are frozen shut. thanks

[Banjo]

Sometimes, in older vehicles, the defroster and heater don't work well (or push hard, or where they are supposed to) because the doors inside the box are vacuum controlled and the vacuum line is disconnected or broken off during underhood work. Just trying to help someone, Banjo.

[fordman]

these trucks are old enough that they have cables for the doors. the 73-79 started having the vacuum controled doors on the heaters.

[flyboy2610]

Alright, so i have officially decided to rebuild the heater box. how hard of a job and what parts are required when rebuilding the box completely? i have a feeling that the flaper doors are frozen shut. thanks

It's not hard to get out. I'm assuming you dont have AC. Disconect the hoses from the heater core in the engine compartment. Disconnect the cable from the heater control valve on the heater hose. Inside the cab, disconnect the vent connections and loosen the defrost hoses under the dash. From the engine compartment rempve the three nuts holding the box to the firewall. Inside the cab gently lower the box down and draw a diagram of where the cable are located, along with anything else you need to remember. Disconnect the cables and electrical wires and withdraw the box from the vehicle.
Have fun at the workbench.

[lrjetmech]

Thanks, flyboy2610, for finally answering the question on how it actually comes out of the vehicle!
My cables were binding up, got that fixed okay, but wanted to remove the box and lube everything up good-now I know how to!!!!!!!!!!

[mrsnicks]

I may do this myself so keep us updated or do a tutorial. Where can you get new seals/foam for the flapper door? Where can you get new defrost hoses?

Thanks,
Patrick

[studdmstr]

I also rebuilt all the flaps in the box too, which were all rusted up and the foam was falling off. Blasted, painted, and refoamed - they work like new.

What did you use to refoam the flaps?

[fordman]

someone had suggested to get it from a hobby store.