Updated: Dec 27, 2019
Restoration of the Heater Controls
As promised at the end of the last post, we are ready to show the work completed on the original heater controls. Last year I happened to run across an incomplete heater control assembly that someone had tried to restore. The work was unsuccessful but what I had noticed was that the face plates (there are three) were all new. Everything attached to the control unit was completely disassembled, and the pictures below show the detail of the work.
Yep, mama let me lay everything out on the dining room table. The temperature out in the garage was pushing double digits so maybe she felt sorry for me. Whatever the case I was glad to have the workbench, er... dining room table, to spread out the cables, original wiring, and all of the hardware. Most of the parts were removed from the Heater Control Assembly by simply taking out a screw or sliding off a clip. However, the main cavity that held the light bulb (and also held the weight of the entire lever mechanism to the bezel) was pinned to the bezel itself. The face plates were also pinned, but not quite as deeply as the main cavity. The pins had to be ground down before anything would move.
The lever assembly and other parts were cleaned with paint thinner to remove grease, grime, and... yes, paint. It seems that the previous owner back in the 80's had left the Heater Control Assembly in the car when it was last painted and there was quite a bit of overspray on the rear of the controls. The picture below shows an oddity. Evidently Ford had two versions of this unit - for the two units that I disassembled their light cavities shown below did not match in pin boss size. Go figure. They could not be swapped from bezel to bezel. Everything else was able to be swapped as needed should a small part or two need to replaced. I did end up testing the heater switch on the table by hooking up a 12 volt power source and light bulb. It passed the test.
Here is something interesting:
The two pictures above show the backing plate in the light cavity. It is made of brass? and I assumed it is used for two reasons. 1. To protect the plastic face plate from the heat the bulb makes and 2. To diffuse light so things are not so bright as the light comes through the letters. You can see the words burned into the metal plate.
I polished up both bezels and one was definitely a winner over the other.
The lever assembly was lubricated with white lithium grease and checked for proper operation. I also took some time clean, sand, and paint the knobs. Each one is held in with a set screw to each particular lever.
Everything was reassembled on the bench. The light cavity was placed back on the bezel after the label plate and brass backing were in position. Since I had ground the pins down I used JB Weld epoxy to secure things and after a 24 hour set time resumed the work. Even the cables that operated the blend door in the heater plenum and the cable that operated the thermostatic control were installed on the assembly before going back into the dash. The wiring was left off so that it could be run from the heater blower under the hood. The power wire was also located under the dash and queued up, ready to go. One cable was already under the dash - the longest one - because it operates the vent door on the passenger side of the car. Thankfully the wiring and cable slid out of the hole of dash enough to attach each one to the Heater Control Assembly before installing it permanently in the dash.
The whole assembly just hung in position as different parts of the wiring and cables were slid back, close to their own attachment points under the dash.
Once the unit was in place, the three nuts that secure the studs to the dash were tightened down and the cables to the blend door and the thermostatic control were installed on their posts. This cannot be done unless the glove box is removed - you can see the access needed.
I did take some video of the work just as a point of reference.
Next up will be the retro fitting of a modern radio and speaker set that works flawlessly well in that odd shaped radio mount for the original 1955 Ford dash!