DCC for Spectrum EMD SD45 #11625

[Capt. Brigg]

I recently acquired two Spectrum, EMD SD45 NP  Diesels. I visited the Bachmann booth at the Portland 2015 NMRA train show to learn how to remove the shell from the frame (thanks guys.) I'm now interested in suggestions on the best way to add a DCC decoder (no sound). I have added decoders to some of my Atlas engines and am good at soldering. I'm comfortable that I will eventually figure things out myself, but would appreciate any suggestions to keep me from having to make all the mistakes.  I'm also interested in if I should glue the hand rails onto the body as they keep falling off, and I'm missing the small screw that holds one of the coupler boxes onto the shell. Where can I get a replacement or what size is it?
Thanks for any suggestions. Capt. Brigg CEO, Pacific Cascade Ry. in HO.

[Len]

The SD45 should be DCC Ready, with an 8-pin decoder socket. Use a decoder with a short harness, as shown here:

http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Bachmann/Spectrum_SD45/bachman_spectrum_sd45.htm

Any short harness decoder will work, I just reference the TCS site because they have pretty decent instructions. Also note the problem mentioned in the instructions of running long hood forward could have been fixed by changing the value in CV29, rather than rewiring.

A handy CV Value Calculator can be found on the Digitrax site at:

http://www.digitrax.com/support/cv/calculators/

Len

[Capt. Brigg]

The SD45 should be DCC Ready, with an 8-pin decoder socket. Use a decoder with a short harness, as shown here:

Sorry Len, no decoder socket, just a long insulation strip with lights at each end, pined to the top of the frame. Probably pre-DCC  installed sockets.   But thanks anyway. I will visit the link you posted to see if there are any other instructions.

[Len]

Are you talking about something like the SD40-2 in this exploded diagram?

http://www.bachmanntrains.com/home-usa/dwg/dwgs/H609X_IS002-B.PDF

Len

[Capt. Brigg]

Len, the "light board" looks like the one in the diagram, but the frame on my SD45 is split vertically with at least three screws holding the sides together. The light board also has four little "fingers" holding it on top of the frame. I tried to upload a picture of the frame but it was apparently more than 128 KB in size. I'll try to downsize a picture and try to upload it again. Thanks for your continued interest.

[richardl]

Len, the "light board" looks like the one in the diagram, but the frame on my SD45 is split vertically with at least three screws holding the sides together. The light board also has four little "fingers" holding it on top of the frame. I tried to upload a picture of the frame but it was apparently more than 128 KB in size. I'll try to downsize a picture and try to upload it again. Thanks for your continued interest.

Welcome.

Standard Operating Procedure for these forums is to use a photo hosting site like Photo Bucket or Flicker.
Scroll down to General Questions for the procedure.
Easy enough to do.

Rich

[Capt. Brigg]

This was not easy to get a Photobucket account.

Hopefully this shows the frame.

[Len]

Split frame locos are not simple to install decoders in, especially as there's not a lot of space to put one either.

It's not the same loco, but the innards are close enough, this should give you a fair idea of one way to do it:

http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Bachmann/Spectrum_Dash_8-40CW/Spectrum%20Dash%208-40CW.html

There are some other ideas on decoder installs in Bachmann HO split frame locos at:

http://www.ppdnmra.com/decoder-inst.pdf

Len

[Capt. Brigg]

Len, once again you came through with some very good ideas and pictures, thanks. Why did you decide to leave the motor lead wires in tact rather than cut them off like in the second description? Also, did you find going directly to the truck pickups with wire better than coming off the frame as he did? Time to take things apart and start learning.  

[Len]

Neither of those are mine, I got rid of all my split frame diesels long ago, so I have no idea why he decided to leave the motor leads intact. If I were doing it, I would have cut the original leads in half, soldered to them rather than right over the brushes, and put heat shrink tubing over the connection.

I would think bringing power directly from the trucks would be better, but it might be more hassle. Which could be why he drilled and tapped the frame for a power lead. I've done that with some older Athearn units after isolating the bottom connection to the motor.

Len

[Capt. Brigg]

Thank you very much Len.
I'm sure you have helped me avoid at least a half dozen errors working with these unfamiliar engines.  
Do you work for Bachmann? They should pay you.  
My other questions were, should I glue the hand rails on, and where can I get a replacement screw for the coupler box?

[richardl]

This was not easy to get a Photobucket account.

Hopefully this shows the frame.

There is a little learning curve but it looks good. You can see how a picture is worth a thousand words. Good job.
You can use You Tube if you ever decide to post a video.

Rich

[richardl]

I have put a Digitrax DZ125 decoder into a spilt frame HO Plymouth switcher. Very small decoder.
TCS has a nice small decoder as was mentioned.
I had to isolate the motor contacts. They come with just wires for soldering or an eight pin plug. Believe they have been upgraded to a different part number. It work pretty good. The main issue is poor pick-up from the track. DCC needs constant pickup which some older Bachmann locos did not have.
I did this just to see if it would work. Motor current was less than one amp so I knew it would work.

Rich