# Need help installing a decoder in Bachman EMD SD40-2 Diesel Loco



## nemo (Aug 20, 2011)

Can somebody assist me installing a decoder in a Bachman EMD S-2 Diesel Loco. What type of digitrax decoder is recommend?


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## Artieiii (Apr 25, 2011)

The choice is yours on what decoder to install. I do not own one of those models but I would be happy to assist in any way I can. I put a Digitrax SDH164D (decoder with sound about $40) in my Bachmann Spectrum F40PH recently. I had just enough room for the included speaker in the underside gas tank. If you post pictures with the shell off I may be able to help more.
-Art


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## Massey (Apr 16, 2011)

There are a couple of versions of that engine from Bachmann. Remove the shell and snap a few pics for us, and we can better help you with the decoder install. It could be as simple as using a Digitrax 163IP that just plugs in or you may need to hard wire it in, depending on the generation of your engine.

Massey


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## gc53dfgc (Apr 13, 2010)

http://www.modeltrainforum.com/showthread.php?t=5603

I installed DCC/Sound in mine so just converting to DCC will be simple enough I suggest using the HD123D or a drop in replacement for the standard ones in them. If you go the DH123D like me then follow the instructions for the GP-38 and the SD40-2 as both are sort of the same in terms of the install.


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## Massey (Apr 16, 2011)

GC the engines you were modifying are the older Bachmann's I was talking about that dont have a circuit board and have a split frame/full frame. It looks like you were having some good fun with those mods. My little Spectrum 44ton loco is a completely different critter than yours is. I have only one motor with flywheels and a DCC plug on the circuit board. THere is not alot of room for the decoder but if you have a decoder that has the pins right on the board it will fit pretty ok. Something like a DH123/163IP will not work well because there is no room for the wires.

Massey


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## NIMT (Jan 6, 2011)

nemo,
I've done more installs than I care to admit.
You really have to give a picture of the loco guts that your working on!
There are several frame, motor, electrical combinations that are possible with that model.
Everyone in this case is right on the possibilities of various decoders available for install.
Along with there being various decoders possible, there are also various frame, motor, lighting isolation requirements that are possible too.


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## gc53dfgc (Apr 13, 2010)

Well my engines did have printed circuts both a previous DCC and then a DC with revesing lights. Both are split frames and thats all Bachmann has made besides the pancake type which I worked on in a PCC trolley which you can also look at. Yeah my 44 tonner is a pain. wiring the two motors properly and isolated fried one decoder. Having about 10 ma for the lighting over the 50ma fried the second and thankfully Digitrax came out with a smaller version of the DZ123 which also offers another light output along with the reverse and forwards so i can keep the cab light that i wanted. So this is the third decoder to go in and once it is all done it will run and look great as well as I will know how to fully install DCC into a 44tonner non DCC ready without any trouble making it just about the smallest DCC engine available aside from Choo Choos/Gregs super tiny japanese train that can amazingly have DCC quickplugged in.


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