2-10-2 decoder replacement

[klemn]

I want to buy a 2-10-2 DCC onboard locomotive but would like to replace the factory decoder with a Tsunami sound decoder.  What is involved in replacing the factory decoder?  Is it as simple as unplugging the factory decoder and plugging in the replacement?  Any help would be appreciated.

Thanks

[ta152h0]

it is as you ask. plug in replacement. however, removing the tender shell is a challenge for bachmann seems to use tight dimensional tolerances and it is easy to break the plastic tabs. I used an MRC 1639 decoder ( with the smaller speaker ) Just note before hand where the number 1 pin is located  for if you install it in reverse, the loco will only run in reverse and nothing else will work. The 2-10-2 looks good on the track ( I do not know how it performs on 18 R track. Are you going to use the originasl decoder elsewhere or throw it away ?

[SteamGene]

The Tsunami does not have an NMRA plug. It is simple to unplug the Bachmann decoder, but you will either need to hardwire the Tsunami or solder the wires to an NMRA plug to make it work.
Gene

[klemn]

Thanks for the info.  I have used some Tsunami decoders in Proto 2000 steamers with the 9 pin to 8 pin harness.  I haven't bought the locomotive yet but I doubt that I would have a use for the Bachmann decoder.  I can't decide between the Bachmann or IHC model.  Both models got good reviews from Model Railroader mag.  Any suggestions?

Thanks again,

klemn

[SteamGene]

The IHC pulls more, but is a generic construct.  The Bachmann is a USRA light Santa Fe.
Gene

[grumpy]

I have one of each and the Bachman is the best looking because it is specific with more detail . They both run well . It is my opinion that it would be easier to install a decoder in the Bachman loco.
Don.

[klemn]

Thanks for the suggestions.  I don't have a huge layout, so pulling large numbers of freight cars is not a concern.  I usually go with about 14-15 cars on a long train.  I decided to go with the Bachmann because I liked the looks of the locomotive better than I did the IHC. 

Thanks,

klemn

[hornem]

I am working on the same project. I have a USRA Light 2-10-2 Spectrum apart and have installed the speaker in the tender. I want to hard wire the Tsunami and replace the original decoder and plug and play board. However I am not sure which wires coming form the engine are correct. There are two connectors one has 4 pins and the other two. The two pin has a red and back wire which I assume is track pickup as they connect to the board in the same location as the tender pickup wires are connected. As for as the four pin I have a red, orange, brown and yellow wire. Any idea which is motor + and motor - and the + & - headlight? Thanks

[nyoun]

I have finished two installations of the Tsunami medium steam decoders in the USRA 12,000 gal. tender that comes on both the USRA light 2-10-2 and heavy 4-8-2.  They are wired differently though they are the same castings.  I concluded that the easiest solution was to splice a short Digitrax decoder wiring harness onto the shortened Tsunami wires.  It was then "plug and further modify".  The coal load casting comes right out of the coal "bunker" which was fully formed, making a perfect speaker chamber.  I drilled many small holes (#55) in the coal load.  I made a baffle to mount the speaker and glued it (with the speaker mounted to it) to the inside of the coal load as high up as possible, drilled two small holes in the bottom of the coal bunker for the wires and used latex caulk to seal the wires in the holes.  What I found is that, even with the very flat Digitrax plug, there is not a whole lot of room for the decoder when you reassemble it - be very careful.  I found that even double stick foam tape can add too much thickness.  Put the decoder on its side against the engineer's side of the tender, as far back as it will go and tape it in with the textured scotch tape that wound nurses use.  The Tsunami is VERY programable and the instruction manual on their web site is both readable and thorough.  Its  hundreds of pages and following the instructions you can really make your locomotives "sit up and bark". 
I really miss the good old days of simple two wire DC.  My fun lies elsewhere, not in cutting edge electronics.