Hello. I apologize if i am going about this the wrong way but i dont see this as a topic anywhere. I had to remove the suburban furnace to replace control board and like an idiot did not keep track of wiring. Apparently something in the connections, possibly a ground, was disconnected and the overhead lights no longer work. Back to the furnace. I have a mack thermostat that controls the furnace and a/c. Looks like the white wire in thermostat calls the power to heat. So my ultimate question is this: there are four wires under the cabinet that were disconnected. Green/white power wire directly from fuse panel. 1 white wire that has continuity from thermostat. Another white wire and a white/yellow wire that i cannot trace to anything. So there are two power wires. 1 constant power and 1 when heat called. I for the life of me figure out how to rewire this thing. None of these appear to be a ground and there are no other thermo wires so i am assuming the two blues were originally connected. Sorry for the long winded story. Any help would be greatly appreciated.