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New Member
Hello everybody,

This is my first post. I got back to this hobby one month ago after 30 years. I built a ho layout with code 83 flex-track and a series of turb outs, then I bought the first locomotives, an Athearn RS3 (which made a terrible sudden grinding sound and I sent it to Athearn last week) an Atlas HH660 and last week a Proto 2000 SD60. Since I will upgrade the system to DCC in the next few weeks, When I bought the SD60 they suggested to get the dcc card and they gave me a digitrax card "that works with the stock lights so you don't have to rewire it). Needless to say, since I had never put together a locomotive, I broke the one of front light bulbs. Then the other one stopped working as well. My question is: as far as I understand it, if I wanted to replace the existing light bulbs with led, the existing circuit (1.5 volts??) would not provide enough tension for a led, correct? Since also the dcc card is designed to work with the 1.5volts, is there a way to rewire the system do that I can replace the bulbs with LEDs? Do I need to get a different dcc module?? Any advise you might have is very much appreciated.

Thank you,



HO & O (3-rail) trainman
I use the Digitrax DH165L0 for a drop-in non-sound decoder for Proto 2000.

The issue with the P2K GP38-2 and SD60s is that P2K wired two sets of bulbs (1 headlight, 1 front numberboards, 1 rear light, 1 rear numberboards). As wired from the factory, the numberboard lights are wired in a way which will burn up the decoder. The simple fix is to just remove the numberboard lights (the light bleed from the head light will still illuminate them, just not as brightly) front and back and be done.

If you want to replace the headlight and rear light with LEDs, then you'll just have to get a 3mm 3.2v LED (I like golden whites) and a 680 Ohm resistor (one for each), and some wire and heat shrink tubing. Use the old bulb's wire length as a guide, and I wire the resistor to the anode (the longer lead). If you use colored wire, white = headlight (negative) and blue = common (headlight and rear light positive), and yellow = rear light (negative). The white wire will go to the NMRA plug that plugs into the top of the old light board/new decoder and the yellow will go to the NMRA plug (where the rear light's light went). Both blue wires will go to where the blue wire went originally to the NMRA plug.

After wiring, if it doesn't work, just reverse where those lights came into the NMRA plug since sometimes P2K wires stuff in backwards (LEDs are polarity dependent).


New Member
Man, thanks!! I'm out of town right now, can't wait to get back home and try! I'll let you know what happens this weekend. Thank you


Yes, you'll want to pull out the numberboard lights.

The headlight (which bleeds into the cab by the way, and is very difficult to fix) will illuminate the whole thing (the two bulbs shine into the same light pipe) will be easy to convert to DCC (just use a decoder designed for P2Ks). The headlights use 3 volt bulbs while the numberboard lights use 12 volt bulbs. 12 volt bulbs also run VERY hot (hot enough to melt the plastic in the shell) so if I'd just ditch the numberboard lights if I were you.

Eventually I'll cut the light pipes off near the shell and mount LEDs behind them so that they're not shining into the cab.


New Member
There are a few variations for the lights arrangement as far as I saw when I bought this locomotive: depending on the loco number they have either 3 or 4 lights. Mine has one in the rear and two in the front. My guess is that they're all the same voltage. I'll check when I get home...

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