A/C wiring question

I have just about finished putting my 90mm project truck together. It isn't anything fancy just a weekend truck to help out with the chores around the yard. The truck was one of those plain jane pickups. It didnt even come from the factory with a radio in it much less anything else. I have added power steering and a sliding rear window already and have finally found what I thought was a complete A/C system. Everything appears to be there when I installed it on my truck except for one plug. It has two yellow and one black wires coming out of it and the plug is triangular shaped. one end of it comes out of the firewall with the lines from the evaporator. I have been told it goes to the thermostat housing to a sensor that I dont seem to have. The truck I pulled everything from was a 91 mm (missing the engine and transmission). I have an extra hole in the thermostat housing with a pipe plug in it so I think if what I have been told is correct, then this should be where it goes but none of the auto parts stores have a listing on a third coolant sensor for this truck that has a plug shaped like this. The closest mitsubishi dealership as about a hour away and over the phone they were not any help. Am I on the right track as to where this plug goes and if so does anyone have a part number to the sensor that I need Thanks for any help!

I know it's a month old - but did you resolve this yet?

If not I might be able to help...
Not sure if youre driving a 2.4 or 3.0, but in either case IIRC both engines have 3 sensors in the water outlet. 1 is for the gauge (or light), #2 is for the ECU, and #3 (again, IIRC) is for the A/C cutoff circuit.

If you need more details, I think I can get a pciture of either engine's waer outlet and maybe a schematic out of the FSM. You can also try mitsubishilinks.com and download the FSM yourself (big files though) includes schematics.

Jim