Need advice on removing and replacing the heater/AC box on the engine side on a 81/F250/4x4…. Mine caught on fire due to dropping resistor igniting the leaves on the inside… burned hole in box before I could extinguish the smoldering leaves. Do I need to remove the fender? Found one in a local junk yard which I also have to remove….

 

Bullnose Enthusiasts Forum

Under, "documentation" link you may find info and diagrams.

Have you asked google "how to remove..."

It's just nut's and bolts, look it over, make sure you have the tools, take apart as few pieces as required.

LMC truck.com has a catalog you can download that has lots of diagrams.

Do you have pictures of the damage ?

Did the AC work before this happened ? Do you plan to keep the AC ?

I replaced my heater core a few years ago, it wasn't too hard. If you have AC, it could be a little more work.

 

I can tell you I am happy I got AC in my truck because right now it is 97*f & 50% humidity and they say it will hotter the next few days

I know you can remove 1/2 the box in the engine bay to R&R the evap coil as I have done that with the truck all together.
Now when I R&R the full box both inside and engine bay I did not have the front end or dash in the truck so cant say how easy or hard it will be when together.

I would say start with the parts truck and experiment on how it comes apart so if you break something it will not be that big a deal.
The inside box is the only part that may give you a problem as the dash may need to be un-bolted.
It has been a while since I messed with mine you have screws across the top in the defrost vents, 1 bolt at the bottom to the kick panel on either side and 1 in the center from a brace from bottom of dash to firewall.
You also have the steering column / pedal bracket to bottom of dash.

Now if you dont have to replace the inside half maybe leave it in place but think some of the bolts that hold the 2 parts together you have to get to from inside.
I dont think you have to this crazy on removing the dash.

All to get this assy.
Inside truck side

Engine bay side

Firewall where box bolts up to

Dave ----

 

You can see most of the bolts around the box from the engine side, but there is at least one you have to loosen from the inside. How big is the hole? Why not just patch it with some of that silver tape for now?

 

 

 

Fuzz thank you for the pictures! From the pictures looks like i might be able to remove the box on the engine side. Retired (73) with more time and would like to get this old truck 81 F250 with trailer special package running again….has been sitting for quite a few years, could never get rid of it thinking i want to fix it up…

 

Franklin thanks! I ordered the USB parts manual from LMC a few days ago…The hole is about 2x3 below resistor and burned around resistor…probably could patch southern style but if I can get undamaged box would rather fix it right….Once I get it runnng and issues fixed. Would like to get it restored (wishing)

 

Ok, just saying, this has worked for me for many years, but I don't drive my truck much. That's a resistor from a mid 1970's Jeep. I don't have AC and Ford stopped stocking the OEM part, all they had at the time were AC resistors. I paid $6.00 for that one. It's a common part that you can find if you look around.

 

If you can access it from the outside it might be easiest to patch it with a small piece of sheet metal or metal tape and the cover with pooky (insulating mastic) and paint. Thats what we would do in the AC biz. If it has to come apart you may as well replace the section damaged.