I have used two methods in the past:
1. Most times I have soldered the red and black wires to the brass pickup bars on either side of the diesel locomotive.
2. On other times, I have cut off a small printed circuit board (PCB) that was sandwiched between the frame halves and soldered the red and black wires to them.
The metal used to make the frames is often not easily solderable, but most N scale locos have a pair of brass bars on each side which rub on the tops of each truck, one per side, to transfer track power to the halves of the chassis. You can solder to that. If there is room, you can drive in a pair of small brass screws, one per frame half, and solder to those, like you saw on the HO install - just use a smaller screw. Or use a drop in board replacement decder, those tend to wedge in the frame to get power pickup and then the motor wires attach to two different terminals on the decoder.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hi guys I have run into an issue when installing the decoders in the small N scale locos. You see I have no problems soldering the motor wires on but when it comes to attaching the wires to the sides of the loco (aka red and black wires) I can't seem to get the solder to stick. Sometimes it does an others it don't. How do you guys do this? I saw a youtube of a guy installing a screw but that was on HO and not N so I am really puzzled. Thanks