After dissecting my temperature control unit to install LED's in place of the bulbs, i noticed that the potentiometer that controls the temperature (the electronic part behind the temp ****) was broken: 2 out of 3 of the connections were just hanging off of it. The temp was always a little finicky, but i just assumed that's how these cars were! A little heat when the **** was on the blue dot...that's just cuz it's an 80's car, right?

Anyways, after realizing that my options were
a). buy a used unit on ebay and cross my fingers
b). pay $1000 on ebay for a brand new one (no, i'm not kidding, someone is actually selling a new one for that much!!)
c). try and rig something together

...i chose "c".

My dad had a 10k ohm thumbwheel potentiometer laying around that--as far as we can tell--is no longer made, so you're going to have to figure something out for that part, but to get the ball rolling here's what we did:

The potentiometer (use a 10k, the one shown is only 1k), and i apologize in advance for the blurry pics:




Dissected the original **** and fit the potentiometer into the back of it (note groove that was cut):




Fit the pot onto the back of the ****. On my potentiometer the thumbwheel pops out, leaving a nice "D" shape that matches the original piece quite nicely.

The **** is a self-contained unit, so just about anything you can rig onto the back of it with any amount of cutting/epoxying will work (just make sure you get the "sweep" of the **** set right).




Here's everything just before being epoxied together:




Ready to install:



Wiring was straight-forward, just wire the three connectors to the three connectors on the temp control circuit board, in the same order.


End result: works great!

It seems like this is probably THE common problem on most of these temp control units, as the fiber board the original connectors are printed on just cracks off (that's what happened to mine). The end result is sporadic heating. Here's pics of the "guts" of my original piece:



I don't think radioshack sells these types of pots anymore, but it's worth checking. Otherwise, as long as you get a linear 10k potentiometer you'll be all set!

HUGE thanks to my dad for the help, the suggestions, and everything else!


EDIT: I'm pretty sure the Piher PT15 is what i used, it looks like the PS15 is a heavy duty version of that. Please don't blame me if those part numbers aren't correct...but let me know either way!

 

This couldn't have come at a better time. I get nothing but heat as soon as I move the **** from the coldest setting and I'm pretty sure it's the control unit. Thank you for the post!

 

As far as the pot you have found; there are millions of 10K rotary pots available. A good place to start would be a Newark Electronics catalog. You want to find one that has the correct shaft size and has the same sweep as the original.

It would be good to find a substitute for the snowflake pushbutton as well. This is a push-on push-off type.

 

Yeah, there are quite a few options out there! Did you see my edit? [I think the] "Piher PT15 is what i used, it looks like the PS15 is a heavy duty version of that."

You could definitely use whatever you find, but this one was a pretty easy fit.

 

F-ING AWESOME!!

I was just about to tear into my climate control unit. My original one work great, except for the temp control. I Ebayed one, and only the temp control works on it (no door control). I was going to Frankenstein them together.... This will help!

Thanks Chris

 

I have a love/hate relationship with the internet. I love that it makes information so easy to access. I hate that it gives me a list of stuff to do I would have never considered by myself.

Thanks for this. And any hints for replacing the lights in the CCU? I'd rather keep the incandescents (unless the LEDs match with the rest of the dash's incandescent bulbs?) so if there is a list of bulb types or you have the old ones you took out to cross reference that would be awesome. Pics of it lit up at night would be greatly appreciated

 

LOL, i know the feeling!

Well, i bought a bunch of LEDs on ebay and have been slowly converting my interior over to bright white light, so i'm not sure you want to hear from me! The bulbs themselves are very easy to replace, they just pop into three little receptacles on the main board. I don't know which kind they are, but they're the standard (unobtainable?) little lights that are all over the car.
As for the LEDs in there, they look pretty terrible right now. I had them pointed straight up and there are definite hot spots on the lighting. I'm going to pull it back out this weekend and try to angle the LEDs elsewhere to get a more even glow. It's also not really possible to replace the lights in the **** with LEDs because there's no room for a resistor and the LED (at least the size that i have), which means some parts glow yellow and others glow white. Oh well, it's a project...