Model Railroading > DCC in old Atlas and Athearn Blue Box diesel?

Like many other people out there, I have a sizable diesel fleet comprising of 25+ year old diesels.

Question is, should I install decodes in the older units? I am not talking wide hood width Athearns, but SD4-2s, GP40-2s, and Atlas Alcos.

Are there any on line guides for installs in the older models?

Thanks,
John

I believe that Kalmbach has some books on this subject. My local hobby shop periodically holds clinics re: DCC conversion. You might want to see if your local shop does the same.

you can try looking on youtube also for tutorials

Ed Stewart
Jacksonville, FL

Most locomotives in my fleet are all Blue box SD40-2 and such. They are very easy to istall DCC and run very good. The only real secret is you must isolate the motor from the frame. The first one will be the hardest, after that they are all easy!

KR

On the athearn's, most people take the copper clips off carefully and switch sides. Then electrical tape on the bottom. Where the fitting for the headlight is, most solder the on track wire to that. The other power tabs on the trucks, well a jumper wire from one truck to the other is soldered on and the other track wire is soldered to the front truck tab. Out side of that, it wires in like any other hard wire install. The layout was just moved to a new home and is still in pieces, and boxes, but I can get a pic of one of my old athearn's that have been converted if you need a pic.

It's not very hard to covert the old blue box locomotives to DCC, and I've seen some kits that help the process. Like most people have said, the biggest issue is isolating the motor from the frame, which requires that you remove the motor and push up or remove the contact tabs on the bottom and place electrical tape on the bottom of the motor.

Ted Curphey
Ontario, OR

Here's a photo showing a decoder install in a blue-box SW1500. It's actually pretty easy - just take your time. Follow the advice by others and make sure the motor's isolated.

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Most decoder companies used to offer a wiring harness for blue box locos. All the solder connections were done and there was a plug for a 9 pin decoder. There were new copper clips for the motor to isolate it from the frame. It was a great way to learn what needed to be done to an Athearn locomotive. Once you did a couple units this way it was easy to figure out the way to do it with the 9 wire harness which comes with plug in detectors.

I can not find any of these harnesses available on line anywhere. The Digitrax Big Book of DCC, the Carstens DCC Manual and the Kalmbach DCC project books all do a good job of explaining the connections to be made and cautions to observe with photos.

Posted from Windows Phone OS 7

Over the years the rubber motor mounts get hard and brittle. They should be replaced with the new Athearn mounts with the screws. Athearn will sell them direct if you call them with the part number and the RTR axle sets to replace the old iron wheel sets that get dirty in one trip around the layout.

John,

Here is a picture of one of my GP-40'2 that I have converted to DCC.

It is an Athearn Blue box undec GP-40-2.

I start with the new wheels #ATH40028, pull off the side frames & solder wire to each side, those are the power source to the decoder. I solder a wire to the top & bottom copper strip of the motor. I cut off the two small barbs on the bottom of the motor & put electrical tape under the motor also.

From there I hook up the respective wires to the correct post on the decoder.

The decoders I use are TCS #A6X, these have the step down for 1.5 volt bulbs.

As stated, after you do a couple it becomes much easier.

Second picture is a couple units that have been completed, GP-40, SD-40T & a Rail Power SD-45.

James Evans

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The Curator's decoder diagram does not follow the complete NMRA color standards and you will find that now and then.

You will most commonly find the two input wires are the power from the rails, red and black. All other 7 wires are circuits coming out of the decoder, orange and grey to the motor and white, yellow and blue for lighting. None of these wires should contact the frame anywhere. The black wire may be connected to the frame to pick up left rail power from the top of the trucks. In this photo the black left rail wire is connected to the old headlight bracket which is a direct connection to the rail. The headlight(s) are the three blue, white, yellow wires running into the heat shrink which insulates them from the frame, necessary for DCC operations. The green and violet wires work with the blue wire for bonus lighting but are not part of this decoder wiring harness.

Posted from Windows Phone OS 7



Edited 1 time(s). Last edit at 12/21/14 21:10 by fbe.

James, nice collection of Rio Grande power. I also agree with you about soldering the rail pickup wires right to the trucks instead of relying on the connection between the frame and trucks.

Ted Curphey
Ontario, OR

So, the newer Athearn motor mounts will fit the old blue box frames? If so, that is a nice bonus!

I also assume the Atlas models to be a similar install, maybe a bit easier, since they already have the trucks wired in this method?

John


kdrtrains Wrote:
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> Over the years the rubber motor mounts get hard
> and brittle. They should be replaced with the new
> Athearn mounts with the screws. Athearn will sell
> them direct if you call them with the part number
> and the RTR axle sets to replace the old iron
> wheel sets that get dirty in one trip around the
> layout.

Go to http://www.tcsdcc.com/

In the left column click on installation pictures. Choose your scale.

Bear in mind they always recommend a TCS decoder, it's their
site afterall. Whether you use theirs or not is your decision to
make.

Larry

I just did an old Atlas/KATO RSD5 with an NCE DA SR drop in decoder. I did have to solder some truck wire extensions to reach the decoder and a couple of wire equipped leds for the headlights. It was an enjoyable experience and the unit runs well.

Posted from Windows Phone OS 7