Installing DCC in GP40

[Jay]

I have recently received a Bachmann GP40 that I am repainting to match a short line that runs in my area.  This is a DC engine and I would like to convert it to DCC.  Has any done this?  More specifically does the motor need to be isolated?  From what I can see my first thought is yes but I would like to also hear from someone who has done it as well.  Thanks!

[djp]

Jay, the EMD GP40 is a very simple and straight forward engine to install a decoder in. It was my first engine and was quite easy. The motor is already isolated. When you open the engine you will see that it is mounted on rubber 'O' rings. To satisfy yourself, get a multimeter and put it on resistance scale. Touch the motor terminals one by one to the wheels one by one as well. If you do not get a reading then you are home and dry. No need to isolate the motor. If you do get a reading [i doubt it] then you will have to isolate the motor by slipping a thin piece of rubber under the motor where it touches the frame. The most methodical way to start is to remove all the existing wires. Use black wire for the left pickup and red for the right. Solder the wires to the respective pick-up's on the wheels. The rest follows as red to the red wire of the decoder black to black. The orange wire [ from the decoder] goes to the higher motor terminal and the grey to the lower terminal. White goes to the forward headlight [you do not need a resister as the bulb is 12V and is not a diode] and yellow is rear. The blue wire is the common for the lights. After these connections do not assemble the body casing. Put the locomotive on the track and test it with wires and decoder hanging and all. If you find that the loco is going in reverse when you press forward on your command station simple reverse the orange and grey wire. I have a very fuzzy picture of my EMD GP40. if you would like to see it let me know. Any further help i can give you, just yell. Steam engines are a little more painful to install a decoder in. Actually getting the body off and breaking down the rest of the engine is the hard part. Diesels are much easier.

[Jay]

Djp,

Thanks for the information on how to move forward on this project.  I am in the process of painting the shell and thought since I have it apart it would be a good time for the DCC install.  I would appreciate a pic, fuzzy or not, as I am always looking for information to put in the library of knowledge.  Thanks again!!

[djp]

Jay, i have mailed you the pictures. For some reason photobucket was not opening otherwise i would have posted the link over here. Good luck with the install and do let me know how it works out.

[tmax500]

what would be the best DCC decoder for the engine?  I would myself like to upgrade to dcc someday and I don't know where to start.  Thanks for the help!

[Frisco]

The Digitrax 123 series decoder would be the best in my opion. Also TCS and NCE decoders are good.

[Running Bear]

I've had good luck using the Digitrax DZ125 decoder. It's Z Scale but can handle HO equipment and owing to it's small size can fit almost anywhere.

[pdlethbridge]

I looked through the motive power here at the Bachmann site and it became very clear that they mark their models 3 ways. Regular, DCC ready and DCC equipped. It looks like you'll have to insulate the motor brushes from the chassis. The regular diesels in the Bachmann line come 3 ways, not decoder ready, decoder ready and decoder equipped. The spectrum line has decoder ready and decoder equipped. The new versions of the regular line only say in their product review that they have 8 wheel drive. The article below shows how to install a decoder in a regular diesel.
http://www.members.shaw.ca/sask.rail/dcc/tmaster/tmaster.html

[Running Bear]

That's a Spectrum Series Baby Trainmaster, not a standard line GP40. I have a standard line GP40 and it doesn;t have flywheels nor was the motor grounded to the frame.

[pdlethbridge]

yes, but it is an old spectrum. not even DCC ready