GRJ,
Just curious - when the relay is closed, the circuit use 4 bridge rectifiers to drop the voltage to the smoke unit when the cab light is on. When the cab light is off, it looks like you're still using 2 bridge rectifiers to drop the voltage to the smoke unit. Did you not want the full voltage from the R2LC smoke output in this situation? Is this for a 20 ohm smoke resistor situation?
Thanks!!