The Evaporator / Blower Motor Plenum Part 4

This is the mode door. It was really rusty before.

This is the weatherstrip I used to seal the door sides against the mating openings.

Works well, correct thickness and durometer for this application.

Instead of the original rivets I just use all stainless hardware to assemble. Heaven forbid if this has to come apart again, but if it should ever have to, it'll be a whole lot easier than before.

The top brace that holds the thermostats and mode door switch.

That back brace is next.

This is messy as the sealing is done by Automotive Bedding Compound and it's almost as bad as Butyl. This is very messy and smears and spreads everywhere. Ug...

Now it's starting to look like a stable plenum again.

This is the cooked blower resistor. I simply wet sanded all the burn marks off it and clear coated it. Looks pretty good and it is electrically intact.

Both of these parts are ready to go back on.

Next is the heater thermostat. These are the over the top unnecessarily complex water control devices. Ford would have been better running the Bowden cable to an actual coolant valve to throttle the temperature of the core.

This heater control valve has two needle valves inside along with a bi-metal thermal strip and diaphragm. They can be taken apart and sometimes cleaned as that's all most need. However if the diaphragm is ruptured just get a new or another one.

Side hose clamp to install.

Here you can see the heater thermostat bi-metal strip sampling air temperature inside the plenum. The idea Ford had with this is it would hold the heated air temperature out of the floor or defrost constant at your HOT- COLD setting. It would increase or dump vacuum to the coolant valve to control heater core temperature.

continued in next post.