1969 B-body A/C - Heater box overhaul , wanna follow along ?

[gtx6970]

1969 Has one of these, 1967 does not

[gtx6970]

I think I need one.

[Rolling_Thunder]

I have a 68 and a 69 A/C plenum in my shed...   restoration projects for one of these days... 

[PatrickPeeters]

Nice job, have to get started on mine. gonna be a lot of hours of tinkering

[richRTSE]

Excellent post Bill, and great picts!  I wish I would have had this to follow last summer when I did mine...

The blend air door has a foam seals on both sides and needs to be removed to install said foam .
To remove the blend air door, just bend these tabs back that hold it in and lift straight out.You don't have to get to carried away so don't go to far and break one off.

I will add this though, I was able to do both of these seals with out removing the door. I used a portable sand blaster to clean it up inside and out, then painted it and glued in the seals and insulation. So if someone is worried about breaking the tabs, it can be done without taking the door off...

Rich   

[Chatt69chgr]

I wonder about that thermal time delay control.  How would you know if it was good?  And if it isn't where would you get one?

[y3chargerrt]

I believe if its working your a/c compressor will cycle on and off with the defrost on.

They are not hard to find NOS

http://www.ebay.com/itm/Mopar-NOS-Relay-1968-1969-1970-1971-Dodge-Challenger-/7931866722?hash=item1d8c6ae62&item=7931866722&pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr

[bill440rt]

AWESOME write-up, Bill!   

[gtx6970]

I believe if its working your a/c compressor will cycle on and off with the defrost on.

They are not hard to find NOS

http://www.ebay.com/itm/Mopar-NOS-Relay-1968-1969-1970-1971-Dodge-Challenger-/7931866722?hash=item1d8c6ae62&item=7931866722&pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr

Correct,
If I remember correctly, the main purpose was to cycle the compressor during defrost mode to -
1 - add moisture to the air hitting your face and
2- cycle the compressor during winter months

Not to hard to find, I have 2 or 3 NOS ones here

[gtx6970]

Make sure you put the 5  steel spacers over the mounting studs , followed by the white foam seals.

[gtx6970]

I used mag wheel cleaner of the Evap core tubes with a brass brush follwed by simple green and steel wool.
All the seals needed are in the DMT kit.

[gtx6970]

Make sure you attach the link from the center vent door to the internal control valve. Before you install the plastic duct

[gtx6970]

Clean up the center duct and with the new foam seal installed , attach it on the box with 3 new #10  5/16" hex head screws.
FYI, I have seen some boxes where this duct is attached with a #10 phillips head screw.

[gtx6970]

The box is now back in the car btw.
I would add if you have someone to help, take advantige if that. The boxes are kind of heavy and awkward to handle by yourself.
If your going to cover the firewall with a Dynomat type material , now is the time do it.
Also the insulation along the top of the cowl above the box is also being replaced.

[gtx6970]

I'm on the lockout for a better condition pass side flex vent( hint hint ) this has a 1" hole in it.
So, untill then.
I turned my attention to the dash controls themselves.
Again, not hard to do but it'll make for a really nice appearence once it's all back in the car.

Take a couple before pictures to revert back to for a re-assembly aid.

[gtx6970]

To remove the knobs from the vacuum switch is real easy, Using a small flat bladed screw driver inserted between the 2 and simply push the black knob off the switch .

[gtx6970]

What your looking for in a finished product is what determines just how far you go . Me, I took it all the way down to just an empty chrome bezel( as you cen tell from the before pics - it was a dusty dirty mess)

[gtx6970]

The fan switch felt like it could be made to operate a bit smoother.
So ,,,, I opened it up to investigate. piece of cake .
Soaked the housing in some evaporust for maybe 2 hours.
Cleaned up the internal slide portion, lube it with some di-electric grease and simply re-assembled. Works SO much smoother now

[gtx6970]

I just lightly glass beaded the actual housing, taped it up and resprayed the black section with satin black engine enamel.
While the paint dries, turn your attention to the knobs themselves.
Finding NOS or mint used ones where the lettering is intact is hopeless, so don't bother.
I used the knob decals from Premium Dash decals.
And I'll mention here. If you get close enough your not going to fool anyone that these are not decals, but from the drivers seat, they'll be just fine.
These pictures really accentuates them but trust me , at arms length you can't tell.

I would suggest once the decals are on the knobs, take a fine tip sharpie and go over the edges of the decal. Apparently the decals are printed on white paper and the edges show against the black knob ( I did that after this picture was taken btw )

[gtx6970]

Clean up your wiring, vacumm hoses, make sure the temp control cable operates nice and smooth.
Then just re-assemble everything and ck your work.
PS- the 2 circlular push clips that hold the lever and temp cable  in place is a 3/16"

[gtx6970]

ps, I should mention.
If you remove the plastic lens from the chrome hsg.
It's pretty easy to re-install .
Just lay the lens over the 3 studs that protrude up ever so slightly and push it back over them, I used 2 small flat bladed screwdrivers and just worked it back over the studs.

If your not comfortable doing that. You could probably use a thin double sided tape to re-attach it

[66FBCharger]

 

[440]

Can you buff the buttons with a plastic polish and soft cotton wheel to restore them back to a rich black... They all seem to go a chalky white, I know you have to remove enough material to get back to "good" plastic but are the efforts worth it ?   

[gtx6970]

The flash makes it show more than it really is.
This is the 1st time I've used the knob decals and didn't think about any issues like this  before hand. So I wasn't prepaired for it.

I think once in the car they will be fine.

[Dino]

Can you buff the buttons with a plastic polish and soft cotton wheel to restore them back to a rich black... They all seem to go a chalky white, I know you have to remove enough material to get back to "good" plastic but are the efforts worth it ?   

My a/c control knobs go from black to white, one is slightly green!  In short, yes you can restore them.

I just did one, I used a 400 grit wet sandpaper to make the knob lok like new again, meaning those scratches and streaks were gone.  Then you have to go progressively lighter to bring them back to a high luster black.  A drop of plastic polish will leave them looking as new.  BUT since the indented lettering is already fading in many spots, this process will make it worse.  If you still have a good outline from the letters then before you sand and polish ypu need to re engrave these so they are deep enough to hold paint.  I tried one and it worked ok, not perfect though so I need to find another tool.  There's no harm in trying.  If it fails you go the decal route.  The decals from performance car graphics have extra tabs on them so you can bend them around the knobs, they may or may not work better.