Dean As you have had no response to your inquiry to Big Boy installation this is what I encountered with an Aheran challenger 4-6-6-2 current manufacture. This has to be very close to Big Boy. I have installed LM3S to tender and hard-wired with a 30 m.m. speaker in box bonded to under side of top of tender, very happy with sound. The plug in connection between tender and locomotive has 6 conductors and the circuit board runs the length of the boiler. This all works fine - un-touched. The number board is on all the time with no control as is the supply for smoke. I desired to use the smoke but I required to turn it off and there is certainly no room to put a switch. The head-light has complete control and there is a resistor on the board. I have created an external switch - I won't go into that here. Aheran recommend Seuthe no. 9 generator. I found this too effective and changed to a 10. It has a higher voltage rating and the actual generator is about .5 m.m. short had to extend. Bad design by Aheran. Everything works beautifully very happy with this model' Hope this is close enough for what you require. Graham.
