Electronic T'stat Module, AC Diagram, and White Smoke 1984 D150

So, I bought a really straight and clean barn kept 1983-84 (built in 8/83) Dodge Ram Pickup for 900 bucks from a kid in Nashville. The interior is immaculate and the body is really straight...the engine and transmission are both very strong....I have a series of questions:

1. There was an UNMARKED blue box containing a circuit board behind the dash. I am certain it connects to the AC/HEATER?DEFROST slider switch on the AC unit. There are NO markings on the box to help find the part. I need a new part because the one I pulled was fried...like caught on fire and melted. I know it is part of my problem because when I slide the selector switch from AC to heat OR defrost the blower motor cuts out. The blower works GREAT (at all three speeds) when AC is selected, but as soon as the slider hits HEAT OR DEFROST the blower cuts out. So I went to the junk yard to see if I could find a similar part...I found an 86 dodge ram SWB and it had different components, but I did find a module in the same place that ALSO had a potentiometer on the circuit board LIKE the original UNMARKED part and it says, "Electronic T'Stat Module" which I assume means Electronic THERMOSTAT Module......

2. My truck has all the components for the AC to work, but someone ripped the wiring up UNDER the hood. Does anyone have a schematic or diagram?

3. Lastly, upon start up, my truck smokes white smoke...NOT CONDENSATION...could it be caused by sticking valves?

Any guidance on these things would be GREATLY appreciated!!!!