Hi,
I have an older HO 4-4-0 Modern Richmond loco, model #83402, on which I would like to install sound. To avoid smoking a new decoder (!), I would really like to find a wiring diagram for the original Bachmann light board. Mine is not the same as the one I've seen on-line in some installation guides.
I'm pretty sure some of the red and black wires are power from the rails, but the pads marked M+, M-, L+, and L- (brown, yellow and orange wires) are a mystery. Which to the motor? Which to the headlight?
Any help would be appreciated!
Thanks,
Brandon
The markings on older Bachmann light boards are fairly consistent. Not all boards have all of these connections:
R: Right Rail Pick-up
L: Left Rail Pick-up
M+: Motor Brush Connected to Right Rail
M-: Motor Brush Connected to Left Rail
L+: Light Positive
L-: Light Negative
B+: Battery Positive*
B-: Battery Negative*
*Some boards allow the addition of a reed switch On/Off controlled battery pack for operation, rather than using track power.
Len
Thanks, Len. That's very helpful... and the board is now making some sense. My loco doesn't have the battery option, but it has two sets of L+ and L-, one of which isn't used: there's no backup light on the tender of this loco.
There's also a third "R" pad at the far end of of the board with a black wire soldered to it. I was confused about that, but I see now it's just the wrong colour wire for the rear tender truck R pickup.
Thanks again. I can do this.
Brandon