Just got a nice little Bachmann Spectrum 45 ton switcher. Nice little loco, but since I run DC, the decoder isn’t either needed or wanted. I’ve found that the decoder has real issues when it comes to low-speed running in DC. So, I’d like to lose it, but I do think those tiny surface-mount LEDs for the headlights are really neat. Any ideas on how to bypass the motor control part of the decoder while keeping the lighting setup?
Edit: Q: Why is a 45-ton loco so much smaller than a 44-ton loco?
Clip the wires going from the decoder to the motor. Run a new set of wires from the wheels to the wires going to the motor. This allows direct feed to the motor from the track while still feeding power to the decoder for the lighting.
Thanks for the reply, Jeff, but unfortunately, it’s not quite that simple on this particular model. No wires from the wheels to the decoder. It’s got a split frame/motor housing, which serves as the direct contact through the main board mounting screws to the main board/decoder for the wheel pickup.
While Bachmann gives the instructions for “Installing a dummy plug” (removing the decoder from the main board - you have to saw it off!), when you follow their instructions, the loco runs backwards. The lights, however, operate properly - that is, when there is positive on the right-hand rail, the “forward” light lights up. Trouble is, when it does, the engine goes in the other direction.
After studying the main board’s design, I’d have to redesign the whole thing, and it’s all surface-mount components. While I’m pretty fair with a soldering iron, no way am I steady enough to scramble around all those components when I’m not real sure even what they are.
For now, I’m just taping over the headlight LED’s until I can figure out what to do about replacing the main board with something a bit simpler in design. I may be able to use your idea, though, now that I’m thinking about it… It’ll require some testing and fitting, I’ll sleep on it for a day or two.