[Trainer]

Rick, The interior electric switch sends a signal to one side of the electric elements control thermostat. If that thermostat is closed, the signal goes onto the signal connection on the relay mounted on the forward wall of the bay. This closes the relay entergizing the two 120 vac power wires going to the electrcal entrance of the heater and from there to the top two connections on the high limit thermostat. And on from there to the two electric elements.

One bottom terminal of the high limit thermostat goes to the 240 vac element. The other bottom terminal with 2 wires goes to the other side of the 240 vac element and to one side of the 120 vac element. The other side of the 120 vac element goes to ground.

Hope this helps you