Model Railroading > DCC Installation

I have several HO engines that are not DCC ready.
Is wiring up the 8 prong connector difficult?
thank you

You could save yourself the hassle of the eight pin connector/motorboard, and hardwire the decoder in? 

Most of my RTR stuff, I hard wired the wires from the 9 pin JST connector (red & black to the track pickups, orange and grey to the motor). Plug in a TCS Decoder, and within minutes you're underway. 

Good luck.

Many companies make a eight pin jumper that can plug into the decoder and the motherboard that can make things simple for you.

If you have some basic soldering skills, it's fairly easy. Use a wet sponge to clean the tip of your hot soldering iron. Anyways the decoder you want for a hardwire install, especially old Athearn Blue Box locomotives is the NCE D13J decoder that is very affordable 4-function decoder and comes in single, 4-packs and 10-packs. It comes with a 9-pin wiring pig tail that the decoder plugs into. I use a dummy plug from a older Athearn RTR model to test run my wiring on DC before plugging in the decoder. The key thing to remember, especially with the Athearn Blue Box locomotives is you MUST isolate the motor from the frame. I usually removed or bent the "scratchers" on the bottom motor clip up out of the way and covered them with electrical tape. I also wrap the decoder in electrical tape to keep it safe from accidental contacts with the frame and other parts.
If you switch the lights to LED's (ultra bright warm white), then use a 1K ohm, 1/8th or 1/4th watt resistors on a wire to each LED. If using the 1.5v microbulbs, that gets a lot more tricky as there is a only limited range between too dim and "poof", and that all depends on the current draw of the lamp. Typically you would use a resistor between 560 and 750 ohms. One method I used in the past was to use a 1k ohm varible resistor, turn it up to full resistance and wire it to the lamps with test leads. Apply power to the setup on the locomotive and VERY slowly turn down the resistance until the lights were the right brightness. Then turn power off and measure the resistance with a multimeter and select the closest resistor to that resistance. The lamps did look better than LED's when you got the brightness right, but the lamps have shorter lifespans and are more tricky to get right. You can calculate the needed resistance by measuring the current draw of the lamps with a 1.5v battery and multimeter as well, but it's not as accurate as the prior method.
The decoders come with instructions and wiring disgrams.

Top 2 photos is a Athearn Blue Box SD40-2 with a NCE D13SRJ (prior model decoder to the D13J) and LED headlights. I soldered right to the metal plates on the trucks by lightly sanding them with a sanding stick, and then tinned the plates with solder and flux prior to attaching the wires. I used a gray wire to connect the trucks to each other, the red wire and black wire go to the decoder which is floating over the rear truck.

The last photo is a Atlas GP40 with LED lights including a nose light hiding there. I have a Athearn dummy plug in the 9-pin pig tail for testing purposes.

Ted Curphey
Ontario, OR



Edited 1 time(s). Last edit at 07/01/26 22:14 by funnelfan.

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My routine with the steel strap on Athearn Blue Box locomotives is to drill and tap a hole for a 2-56 screw. I've had much better luck with a mechanical connection then with trying to solder to that strap.

JunkTrain Wrote:
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> I have several HO engines that are not DCC ready.
> Is wiring up the 8 prong connector difficult?
> thank you

What kind of models are you trying to add DCC to?  That can make a bit of a difference.  Ted's got some great info about doing the Athearn Blue Box units, I've done a few of those and had good luck so far.  It's totally worth the effort.

Nathan

Here is another thought that might help. Go to a train show and buy engines with dcc installed. I bought Intermountain and Genesis this weekend for $35 each. Even had sound units for 50.
Joe