I made a small circuit board to set up automatic climate control in my 91 Camaro. I used a servo motor to adjust the hot-cold blend door that was connected to the hot-cold lever. To the hot-cold lever I used an extra cable and hooked it to a sliding potentiometer. The controller reads in the position of the hot-cold lever and compares it to the temperature in the car and moves the blend door.
I also control the fan speed. If the car is way too cold or hot from where you have it set the fan runs fast until the temperature in the car comes close and the fan slows down.
It also has a light sensor that cools more when the sun is blasting in and warms more at night. There is a sensor on the heather hose, so when it is cold out it waits until the coolant warms up to bring the fan on.
After I got it working in the Camaro a couple of friends had me set it up in their rigs (non f-body.) If there are more people here interested I can post more and provide parts if people want to try it themselves.

I tried to get some pictures:



This shows where the cable attaches to the blend door under the passenger dash. Also it shows the potentiometer attached to the second cable.





This shows the servo where it pushes and pulls the cable going to the blend door. The circuit board is behind the sevo.



This is under the hood, it shows the MOSFET transistor I use to control fan blower speed. It is middle upper left of pic, with gold heatsink on it (it gets HOT.)

If people are interested in this project I will write more about it. Sorry about the crappy pics, it is pretty much invisible with the car put back together. It looks like stock and it works really well.

 

Where is the temp sensor for reading the inside temp and where/how do you set what temp you want?

 

Obviously it has to have a control and display inside. Very creative, Kurtis72.

 

Very innovative. For your next trick, you need to make it a plug-and-play kit we can purchase.

 

I tried different places for the inside temp sensor and ended up hiding it in the air inlet. It is just ahead of the console under the dash, there is a coarse foam filter in it.
The temperature setting uses the factory hot-cold lever. I have it calibrated to 65 on the left cold side and 85 on the right hot setting.

 

kurtis.......that's pretty cool to retro the HVAC in 91 Camaro.
My 14 Acura TL Advance has that set up with the sensors and positioning of the sun and such and I thought it was the coolest thing since sliced bread!

KUDO'S to you!

 

I have a couple of screens for display.




The one on the left is LCD 2 lines of 16 characters. They come in several colors for the backlight. I used it on my friends truck, it displays outside temp.
The smaller one I have not gotten working yet.
The next time I am at the salvage yard I plan to find a rear-view mirror with a display and try to get it hooked up to my system to read outside temperature.

 

It would probably be more kit than plug and play, but I am down with that.
The first few people would have to be patient while I get the bugs worked out.
I need to make some 3d printed brackets. If you check out my plumbers strap and zip tie job in the pictures you will see what I am talking about.

 

NASA NEEDS YOU........LIKE RIGHT NOW!

 

I am definitely interested. Please PM me if you get to a point where you will be making them. I'm in no rush. I'd rather have a quality product than a rushed item. Besides, I still have to install the auto up/down window harness I just bought. Just curious, what would you be thinking of for a ball park figure cost?

Eldon

 

Agreed, the refit is pretty cool. Ironically, my daily drivers have auto temp but I never use it. Somehow I prefer to be the one that decides whether the temp is "blue" or "red", and how loud the blower roars.

 

I am hoping to keep it under $50 for a basic system. Too much?

 

When factoring in parts and labor, I think that's a reasonable cost.

 

Any progress?

 

Here are some more Images:





Shows how stock hot-cold lever connects to variable resistor.





Close up.





This is the circuit board. The CPU plugs into the 28 pin socket.

 

Some, Yes. I had trouble with the voltage regulator I was using and have some more powerful ones on the way. I also discovered that the MOSFET I use for running the blower fan must have its mounting tab isolated from ground.
Both things we learned the hard way, after I had "finished" the install on someone elses vehicle...

 

Hey i did something VERY similar a while back.

I used a Servo for the temp control, a servo for the vent selector, and a thermister for the interior temperature. It all went where the radio/AC used to go and plugged into the stock harness. It was controlled by a microcontroller connected to an Android tablet

 

That is really cool, I love how you used the servo to control the vacuum door actuators, GENIUS. What microcontroller is that? Arduino?
I started with an Arduino Uno and then built my own board after other people started getting interested.
So do you run the AC compressor clutch too? How about the heater core bypass? Do you monitor the engine coolant temperature?
Is most of your programming in the tablet or microcontroller?