The fresh air fan on my '72 doesn't seem to be working. It worked at one time, though. I've found that cleaning all the electrical-related items (especially grounds) usually fixes any issues on my car.

1. The Clymer book states that the "Belden cables" need to be removed. I'm assuming these are the cables that control the opening/closing of the vents? Are they a PITA to get on/off?

2. Any advice on taking the control unit out and cleaning it? Is it easy or hard? I want to know how much time and frustration I can expect.

3. What should I clean? I plan on taking the wires off and cleaning the contacts with a small wire brush on a dremel tool. I will also clean the slider surfaces where everything connects/slides.

4. What should I clean it with? Simple Green? Throttle body or MAP sensor cleaner?

Thanks!

I just went through this on my car. Make sure first, that the three contacts for the fan speed setting aren't melted. It can happen when too much resistance builds up, which causes heat, and then the contacts sink down into the plastic preventing the arm from touching them.
They were melted on mine. Had to sand away the plastic ridges in between the contacts, that were created when the contacts overheated.

Anyway, you can pull out the ashtray, and you'll be able to see all the contacts through there with an auxiliary light. You can reach everything from underneath the dash. I was able to clean all the contacts that way. A little awkward at first, but you figure it out. Easier than removing everything...probably.

BTW, if you're thinking of removing the fresh air box to get at the fan...make sure you have everything you'll ever need, every seal, clamp, hose, etc. Because that's not a job you want to do twice.

Good write up above.

Simple write up.
Remove gas tank.
Remove hoses
Mark and remove all control cables in front, facing you.
Unbolt and tip out from the bottom the air box.
Mark and remove the rear cables
Remove box.

....add:

Plenty of patience.

Double up on curses in at least four different languages because otherwise you'll run out of them whiel reinstalling the airbox....

It may be possible to do this with the wipers fully installed, but I am pretty sure that it was very helpful to remove the wipers and push the wiper arm assembly back up under the cowl to make more room to get the blower box in and out.

It is all definitely a PITA. Accurately mark the location of the cables, both the actuating wire and the outer cable as both will effect correct operation of the blower box. Phone pictures help.

Double check the correct operation of the selector switch. I would hate to wrestle out a blower box and find it was faulty selectors all along

So I was able to pull out the unit from the dash. I needed to remove the wires before doing so.

I cleaned where the brass spring contacts connected to the lever touch the brass contacts (circled area in photo). I also cleaned the wire connectors. They were covered with dirt and crud. I used a wire brush on a dremel and not only removed the grime, but also the corrosion on the all Click to view attachmentbrass pieces.

Changed the bulb as well! Works now! Thanks to all for your help.

i can live with the occasional cloud of mouse nests on my dd rather than refurb this system.

Replacing the cable underneath the air box was probably the most frustrating and patience-trying experience I've ever had with the car. You'll be in the trunk, crouching, cursing, and wondering how the hell this was done at the factory. I would consider removing the frunk lid before attempting.

I'd rather remove and replace the dash pad twice instead of this job.

But you will get a great sense of satisfaction when you feel that cable clip snap into place...

there is no way id remove that system just to clean it out. it is a huge pita. id try all sorts of compressed air and vacuum and tape to create a seal before removing that. and water. and anything else that might work.

Oh that,
Yah that is easy....you got it.