temp controller
 

Hi I am wondering if anyone has seen this temperature control installed in these trucks I have an 81 c10 im trying to convert it back to stock and figure out wiring issue any help is appreciated.

Re: temp controller
 

RH picture looks like you have a chunk of the steel dash and definitely some of the bezel missing where the A/C controls used to bolt in.

In the LH picture it looks like someone completely disassembled the A/C control unit.
If you don't have all the pieces you'll need to find a complete one in a yard.

Left switch is the blower motor switch.
Center??? Does it have a cable attached? If so it might be the temp control.
Left is the Vacuum Mode selector switch. Be careful of those hoses. Be sure to hook them up to the same locations on the new control head and take care not to crunch them up or you'll have leaks.

The 1981 GM Light Truck service manual has a lot on the AC system in Chapter 10.
Schematics are in the back of the service manual.
Download all of the 81 service manuals at the link in my signature.

Re: temp controller
 

It doesn't seem to have steel missing from the dash but the bezeling was broken and removed. I have ordered the stock temperature control unit from lmc for this truck. It appears to only need the switch that was on the left and two cables which are both installed but pushed back in the dash so you can't see them in the pictures. I'm not sure what wires need to be removed or changed to convert this back to the stock installation. i'm also confused as to why it would be switched to have three switches and not have had the cables installed because I don't see how the blocker doors could open or close this way.

Re: temp controller
 

I believe there should only be one cable for the Temp selector lever and door.
All the other doors in the A/C system are controlled with vacuum. The vacuum "Switch" on the left is actually the mode lever that selects MAX AC to DEF.

Re: temp controller
 

So I figured out my confusion.. The previous owner partially turned this truck into air conditioned when from factory it was only heated. I am considering altering his install and using a toggle switch to control compressor and getting an accumilator that i can install a binary pressure switch im not sure what size relay to use for toggle switch and compressor wiring. What are your opinions on this? Switching this to a factory ac would be expensive and a lot of work, also an aftermarket system is very expensive.

Re: temp controller
 

here are some pics

Re: temp controller
 

5 pin 40A Mini ISO relay will switch the compressor clutch.

The dangling mode control switch had vacuum lines attached. What did the PO use for a heater AC box?
Is the evaporator already one of those under dash units?