So in the spirit of my new philosophy, Use it or Sell it, I pulled a like new Bachmann 3 Truck Shay off the shelf for evaluation. This loco was purchased many years ago from an LSC member and it looks as if he never ran it. I plan to do a RailPro install using only the stock boards so that if I decide to sell it, it will be quick to put back to stock.
The model I have is the DC version, but it supports DCC with a 6 Pin plug and some loose wire connections. The loose wire connections are straight forward and are documented in wiring diagrams. I will only use the Motor + and Motor - connections and just disconnect the Railway R and Railway L connections from the screw terminals to isolate the track pick-ups.
Where I am running into questions is the LED lighting and B+ power connections. Here are my questions…
The front and rear LED lamps are marked on the wiring diagram, as Front LED + and Rear LED +. DCC (and RailPro) normally uses current sinking (switched DC -) to control lights. Did Bachmann label this backwards, or did they just design an oddball DCC board for just this purpose? If labeled correctly, I can use a logic inverter to swap it around for the RailPro output.
Then there is the pin labeled B+. Am I correct in assuming that this is a voltage source for the DCC Board?
And finally, If I leave the Railway connections open, am I correct in assuming that I should power the stock electronics by connecting my battery to the Railway screw terminals as well as my RailPro board?
I’m sure I can work this all out on my own with a meter and a power supply, but in the interest of not wasting any of the Magic Smoke, if someone else has done this, (does not need to be RailPro, just battery - R/C) I’d love to hear your findings / solutions.
If the evaluation proves that this will be a valuable asset for my railroad, I’ll cut out all the stock electronics and wire everything directly to gain more control. As an example, on the stock DCC implementation, the Cab Light and Smoke are on the same wire! The smoke does have an on-off switch in the smokebox.
Say what you will about the “Super Socket” in the K-27 and C-19’s. Bachmann learned a lot between releasing the 3 Truck and the K. everything you would ever want is available at the socket, or in the harness if you want to toss the boards (which I do).