HVAC / AC Controls - what goes where? (vacuum lines)

ErikTande · June 26, 2019, 12:12 PM

My AC controls aren't working, is there anywhere I can order a direct replacement? Or an simple conversion? A lot of the plastic is brittle or broken (looks like vaccum lines coming out the back). I need to get my Dash AC working for a couple summer trips coming up.

Rickf1985 · June 26, 2019, 12:51 PM

Most of those controls were either GM or Chrysler pickup truck controls. They swapped around so you will need to compare what you have to new ones. Look at Dodge, Chrysler and Chevrolet controls from around 82 to 86 and you should come up with a match. The vacuum plug may be a little more difficult. It will be the same brand as the control but finding one could be tough. You may need to improvise with individual lines there.

ErikTande · June 26, 2019, 02:48 PM

Oh! I didn't realize it could be a dodge part! I've been looking for a GM unit and couldn't find one that matched. I switched to dodge and found some:
So here's some pics of a unit that looks the same. If I'm lucky those nipples on the back are still intact and I can use some vacuum hose to get them working. I'll pull it this weekend and find out.
Thanks!

ErikTande · June 26, 2019, 04:14 PM

After doing some googling the 88-93 controls connections look identical and I think they're interchangeable, and I can find those easily at the junkyard. (The 80's stuff is hard to find). I might try grab one from the local salvage yard and see if it works.

ErikTande · June 30, 2019, 12:52 AM

Ok so good news, I cleaned up all the electrical connections and got it working (kind of). My fan control works great now (low medium, high, etc).

However, If I select vent, ac, heat, etc air only comes out the defrost by the windshield.

I assume that's because the vacuum lines aren't connected. So I got some tiny vacuum hose to reconnect them which worked great. Unfortunately I have NO IDEA which nipples to connect the 4 colored hoses to. Is there any way to find out??? And would that fix my problem of not being able to select where to send the air?
Thanks!

Rickf1985 · June 30, 2019, 10:16 AM

I have the dash apart in my Pace Arrow, I will see if I can get to the back of the switch to get some pics.

ClydesdaleKevin · June 30, 2019, 07:32 PM

Is this what you are looking for? This was from an 89 Dodge motorhome, but if you do an image search, a whole BUNCH of these come up on Google.

Kev

ErikTande · July 01, 2019, 10:46 AM

Quote from: ClydesdaleKevin on June 30, 2019, 07:32 PM
Is this what you are looking for? This was from an 89 Dodge motorhome, but if you do an image search, a whole BUNCH of these come up on Google.

Kev

No, but thanks! My hoses are red, white, blue and black, but googling it some more I found these diagrams. I'll try this out and see if it works, thanks! I assume I need to plug/cap the unused nipples. We'll see.

this is close, but lists yellow instead of white (probably the same anyway):

this one has my colors and looks the same as the top, so i'll try this:

Rickf1985 · July 01, 2019, 12:00 PM

You may have to experiment with the open nipples because as you change modes some of them may have to vent to atmosphere. Make sure your vacuum supply is hooked up to the vacuum canister under the hood. Engine vacuum alone will not properly work the controls.

ErikTande · July 01, 2019, 04:37 PM

Quote from: Rickf1985 on July 01, 2019, 12:00 PM
You may have to experiment with the open nipples because as you change modes some of them may have to vent to atmosphere. Make sure your vacuum supply is hooked up to the vacuum canister under the hood. Engine vacuum alone will not properly work the controls.

Yeah I'll have to double check that. I started the engine to see if I could feel any vacuum in those tiny red, white, blue and black hoses but I didn't feel any. Might have just been too small to notice though, I'll make sure to check it either way.