What do those of us with '73s do if we want to replace the HVAC controls?

[WranglerTJForum]

I wanted to replace the face plate on my '73 K10 HVAC (with A/C) controls. It's old, it's worn, and it just needs refreshed to match the rest of the interior.

I noticed nobody makes a '73 style HVAC control so I ordered the '74 model which looks like this:

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Unfortunately after comparing it to my '73 HVAC controls, they look like this:

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On the backside of the unit they've got a part that all the vacuum tubes go to (among other things). I was looking closely and even if I managed to get those parts off, they don't look like they'll fit on the '74 model HVAC control unit. It's different in many ways.

What should I do here? Surely someone has encountered this situation before?

 

[PrairieDrifter]

Im a little confused on which one is the original.

A/c vs non a/c is the real difference, and some year changes of course.

 

[ali_c20]

Can you bolt in the 74 unit?
I would try to figure out the vacuum ports and fan switch pin out.
The heater control cable is the same from 73 - 87.

 

[Goldie Driver]

AFAIK, the Max ac units did not appear until 76. Our 75 had the AC style where the lower temp slider turned on Max AC when all the way left and the blower only ran on high. It also looks like the pictured Max unit only has 3 blower speeds which I thought was a much later ( mid to high 80s) vintage.

What unit was in your truck?

 

[75gmck25]

I’m a little confused about what you have purchased.

The back of the controls for my ‘74 look similar to the first picture, and the faceplate looks like the 2nd picture. However, the vacuum connector and electrical assembly on the back of the 2nd picture is totally different than mine.

The old set of controls, with Max setting on the faceplate, is from a newer truck than your ‘73.

My ‘75 would use LMC 32-0645.

 

[legopnuematic]

As stated, please confirm what is in the truck now. The last picture is of an 83+ control.

 

[WranglerTJForum]

Okay, so here's some actual photos I just took.

This is the unit that is currently in my 1973 K10 with A/C:

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And this is the unit I bought from LMC which was listed as being for a '74 with A/C:

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[TotalyHucked]

I believe you're supposed to harvest the other pieces off your original unit, they don't repop the vacuum manifold or that main electrical relay/connection box

 

[WranglerTJForum]

I believe you're supposed to harvest the other pieces off your original unit, they don't repop the vacuum manifold or that main electrical relay/connection box

That's what I was thinking. It looks like I may have to drill some holes as the holes aren't there for those parts.

This '74 unit is very similar to my '73 unit but there are some differences. Guess I'll have to make it work.

Any idea what the best way to clean up that relay and the electrical contact points on it would be?

 

[bucket]

Okay, so here's some actual photos I just took.

This is the unit that is currently in my 1973 K10 with A/C:

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And this is the unit I bought from LMC which was listed as being for a '74 with A/C:

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That one you bought looks like the one in my '79.

I don't think LMC actually knows which ones are correct for a certain year.

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[Radiohead]

This '74 unit is very similar to my '73 unit but there are some differences. Guess I'll have to make it work.

Any idea what the best way to clean up that relay and the electrical contact points on it would be?

Electrical contact cleaner? If you need to burnish the points, maybe a piece of crocus cloth or 1000 grit wet/dry sandpaper and light pressure?

 

[WranglerTJForum]

That one you bought looks like the one in my '79.

I don't think LMC actually knows which ones are correct for a certain year.

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In fairness, USA1 is also selling the same one I bought as the '74 model.

It's hard to even say, honestly. I guess I was figuring that the vacuum tube connector and relay / electrical board were part of it. I can't find those parts for purchase anywhere so maybe they just don't make reproductions of those parts. Not a big deal, I'll just have to spend some time cleaning mine up.

 

[WranglerTJForum]

BTW, so I don't break it in the process, how does that vacuum manifold detach? Is it the phillips screws or does it just pull off?

 

[bucket]

BTW, so I don't break it in the process, how does that vacuum manifold detach? Is it the phillips screws or does it just pull off?

They are barely visible in your picture, but there's some one-way push clips on the two aluminum studs. They are kind of hidden in the dust. They are finicky to remove, but it can be done with some quality needle-nose plyers.

 

[WranglerTJForum]

Got the factory unit off and here it is side-by-side with the '74 unit I bought from LMC.

Doesn't look anything like it, right? No way I can make this work, which makes me wonder what the hell is going on?

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