Trying to get the heat in my damn truck figured out. It's getting cold out and I'm about at wits end.

To recap:
-thermostat is good, and installed correctly
-blend door vacuum switches work (can get air to come out defrost, floor, vent, panel)
-get ambient air to flow through vents while truck is moving (blower motor doens't work).
-both heater hoses connected to the heater core are hot.
-bypassed heater water valve with a ball valve, left vacuum connected to old heater water valve.
-truck originally had A/C, but all components including condenser and compressor have been removed.

New info:
-I open the vacuum door under the dash and can see the heater core and blower motor. The heater core is hot to the touch. Pictures show perhaps a leak.

Is the heater core clogged? Why am I not getting ANY warm air? I figure while driving I should at least be getting luke warm air.

Here are the pictures. I stuck my phone in the vacuum door to get a pic of the inside after I cleaned out all the leaves. Speaking of leaves, if there are a ton of leaves in the box with the heater core, I'm assuming outside air is entering the heater box and taking debris with it. Is this from the cowl?

Please help!

Vacuum door under the dash:


Phone pic from inside the box. You can see the apparent leak at the bottom of the heater core:


This could be why my blower motor doesn't work...


Sheesh...

-MK

 

The blend door is gone. None of your air is going through the heater core.

 

Where does this door belong? Anyone have pictures or a diagram of what its supposed to look like?

 

It fits between the blower motor and the heater core to direct the air straight through the heater core.

I had the same problem on my 79 bronco and had to replace it from one I had laying around. I have no idea why somebody took it out and didn't put it back in.

 

It fits between the blower motor and the heater core to direct the air straight through the heater core.

I had the same problem on my 79 bronco and had to replace it from one I had laying around. I have no idea why somebody took it out and didn't put it back in.

 

Here's the illustration from the Ford parts catalog.
Click on the .pdf link to view.

 

Thanks a bunch. So what am I missing?

 

Looks like you're missing:
Door assy, air damper
D3TZ-18A361-B
Fits 73-up F100/350 w/ integral a/c

Shaft assy, damper door
D3TZ-18C466-A

Shaft, damper door
D3TZ-19A580-A

I couldn't locate any of these parts at the dealers I have access to.

 

So that's the reason I'm not getting any heat from the heater core?

I guess my next question is: it looks simple enough to rig it up to work, so what would I block off and open so I actually DO get heat from the core?

I could probably fab something similar out of metal or plastic, and hand actuate it...

-MK

 

I'm still trying to figure out exactly what is that door blocking off?

 

Just as an FYI.... I can turn the blower fan off on my truck and close all the manual vents and I still get air down on my legs when I'm moving, which can be rather cool on a cold morning. Even with the heater controls set to warm, the air is still cold. Only when I turn on the heater blower fan do I get any warm air.

Your mileage may vary, but in my truck the heater is flat freaking useless unless the blower motor is forcing air through the core. The air I get forced into the cab is NOT going across the core.

 

Ok, so get the blower motor working, get some heat...

Am I correct in assuming that the two wires coming through this bung into my cab are for the blower motor?



They appear to be the same color and size as the wires seen here attached to the blower motor...



Thanks again. I know it's a pain, but I really appreciate you guys walking me through this.

-MK

 

Another thing I should mention is that I get cool air blowing from wherever the selector switch is set when the truck is in motion. I.E. If I have it set on vent, or floor, or defrost, that's where the air comes from. But only when I'm moving, and never hot.

 

Yeah I only have 2 settings, floor or defrost and it doesn't really seem to matter where it's set, I still get air moving through the cab. I really need to figure out where that leak is coming from.

 

So the blower motor would essentially force hot air from the core through the vents. If I had the blend door, it would shut out the outside air?