Renzor heater fan switch

[Dragster Racer]

I have an older Renzor hanging gas heater that I picked up for a song. The gas controler acted up, so a heating friend replaced the gas valve. I have never used the heater to this point.
Now, what it does is light the burner, pauses about 40 seconds, runs the fan, turns out the burner, fan turns off. Start over.
The fan switch only has two wires coming from it. I am thinking that the other two inputs have to be a 110V source for heating the fan switch.
Anyone have expeirence with this?

 

[Dragster Racer]

Figured it out. The new control valve is a little different than the old one. Heater guy had the fan switch preheater hooked up to a terminal that didn't give any voltage, so the switch wasn't working properly. After about 40 minutes of probing with the meter and following the wiring diagram, I figured it out I think. Seems to work properly now.