Why are we talking about the lighting CV board vice the Smoke board when the issue is no smoke fan????? Only the very earliest MTH using a Seuthe smoke unit NO FAN were plugged into the CV board.
Early stuff could use different color wires. Usually Orang Center rail and Brown ground. On the spring pad one is AC up to the Light CV board on all the time. The other is AC up from the Smoke switch. Powered on by the switch. Both get power from the engine center rail red.
You need to remove the smoke unit from the shell. Usually one screw to the bracket on PR steam. Though some articulate use 2 screws. Smoke unit comes out whole and you unplug the connector on smoke unit that has wires going to spring pad. G
