sleeper temperature control

I am trying to find a p/n for the electrical control in the sleeper switch panel. It is a thermostat with a bunch of components and wires on the back side and a round black knob on the front side. It controls the temperature whether it is heat or a/c. This is on a 1993 W9 vin 584764. I have been everywhere on the internet and I can't find so much as a picture of it. Anyone who can give me a correct p/n will be a hero. Thanks Dan