HO scale locos
Athern GP 38-2
Athern GP40-2
My question is, what type of lightbulb do I need? Do I hook the front white wire for the rear light also?
What are the blue, purple, yellow, and green wires for?
Thanks for all your help.
Barent
The manual with each decoder explains the wiring. Generally, the blue wire is the “common” return for all the functions. The white wire goes to the front headlight, and the yellow wire to the back. I don’t have that decoder, but I’d imagine the blue and purple wires support additional functions that you can turn on and off, like ditch lights or Mars lights.
The manual with the locomotive probably says what voltage the bulbs are rated for. If you get a 16-volt bulb, then you can wire it directly. Lower voltage ratings require resistors. LED’s also require resistors. I personally like LEDs, and I’ve replaced the original bulbs in a couple of engines with them.
Blue is the function common, the + side of the functions.
White is the front light. Yellow is for the rear light. Green is F1, purple(violet) is F2.
If you want to use light bulbs, you would connect a 14-16v bulb between the blue and white for front light, and blue and yellow for rear light. To use White LEDs, you will see the LED diagram looks like: -->|— Connect the blue wire to the → side of the LED, and connect the |-- side of the LED to a 1K 1/4 watt resistor, connect the other side of the resistor to the white wire for the front light.
Miniatronics and Model Power make suitable light bulbs.
–Randy