Convert Bachmann G Shay to DCC

Tony Rentschler

Hi Al,

I’m converting an older G scale Bachmann DC two-truck, 36-ton Shay to DCC. I have the new power trucks, which isolate the motor from the track pickups. I’m not using any of the original electronics. I’m adding a speaker and TCS WOW501 steam sound decoder, and I’ll have front and rear headlights. No flickering firebox or cab light.

With the locomotive traveling from left to right, the trucks' wires are as follows (Bachmann does not follow any convention):

Front truck (coupler to the right and gears facing me)
On the right side:
- Orange = track Left
- Brown (or gray or green, I can’t tell) = M-

On the left:
- Red = track Right
- Black = M+

Rear Truck (coupler to the left, gears facing me)
On the right side:
- Orange = track Right
- Brown = M+

On the left:
- Red = track Left
- Black = M-

So even though the front truck travels “forward” and the rear truck in “reverse,” Bachman uses the same color wires on the same sides of each truck. However, Bachman reverses both the track pickups and motor leads in the rear truck. My question is, do I need to reverse both the track pickup wires AND the motor leads in the rear truck at my decoder? Or just the motor leads? I’ll use NMRA convention (red = track right+, black = track left-, orange = motor+, gray = motor-) when I attach my leads from both trucks to the decoder.

I’m stuck trying to puzzle this out.

Thanks for your help.


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