To plug or to hardwire on new locos

[fishindogwood]

So I’ve been a lurker member for quite a few years a still don’t have a layout back up but have all the locos, cars and buildings stacked up in the 100’s.  I’m still positively going Railpro as it’s seems to be far superior to the DCC system, except for a bit of lacking in sound file choices potentially.

Question is as I have a dozen Athearn Genesis with 21pin and 9 pin plugs, 6 Atlas Silver series with 8 pin plugs, should I use an adapter plug to wire LM3s into the existing 9 and 8 pin motherboards or do an aftermarket motherboard like the Nix offerings if room, or just do a total hardwire without a motherboard for space savings?  The 4- 21 pin Athearns are seemingly obvious to plug into with the new 21 pin LM3s probably.  Obviously hardwired for a couple Front Range GP9’s.  Also none of my builds will have any beacons or ditch lights, too early.   So my question is what you you all think I should do for the 8 pin Atlas, and the 9 pin Genesis?     Also I am very good at soldering and electrical work so that is not an issue.      Thank you  for any advice!

[CPRail]

I've done 8 pin, 9 pin, 21 - 9 pin and hard wire installs. I think it all comes down to what you have for space and what you are also including (speaker, Keep-Alive, etc.). Case in point, I've done 5 Rapido SW1200RS installs and for each one I had to toss the board.

While there is room length and width-wise in a Rapido SW1200RS for a LM-3S module (once you un-solder the inductors on the board), due to the angled roof top of an EMD SW, there isn't enough room height-wise for it to sit on top of the board. Hard-wiring also eliminated the extra wires on the 21-9 pin adapter. No idea if the new 21 pin module would make a difference in this install, but there's hope.

For a Bowser SD40-2, you need to sacrifice the space allocated to the speaker enclosure for a normal LM-3S and put a small sugar-cube style speaker under the stack. I suspect the new 21-pin module will drop right in and you can put a bigger speaker in the rear.

[fishindogwood]

I am planning on doing keep alives’, most likely the Railpro one.  I’m also leaning toward utilizing speakers and enclosures from Scale Sound Systems. I guess a new question or possibility is using the new 21 pin LM3s because they are a bit smaller footprint, even though I only need lights for front and back lights, possibly cab and possibly numberboard lights tho I haven even powered any of these locos to see if numberboards are clear or lightable.  Here is a list of most be utilized.

Athearn Genesis: 4- GP18’s,  5- GP-38-2’s,  2- GP-9’s,
    1-GP39x,  1- Mikado 2-8-2
Atlas Silver: 2- GP-40’s high nose,  2- Alco C420 hi nose, 
Atlas Red box: 2- C30-7’s
Atlas/ Kato Yellow box:RS3
Front Range: 2- GP9’s

[CPRail]

I use Scale Sound Speakers exclusively (I think there is still one P2K GP30 that I haven't upgraded yet), so I recommend them. Out of your list, I've done the Athearn Genesis GP9s, a Genesis 2-8-2 and an Atlas redbox GP38 (I guess it's Silver these days?) and an Atlas Silver GP40-2W.

Biggest issue on the GP9s was the Keep-Alive (TCS KA-4) AND retaining the cab interior. I made it happen, but it wasn't elegant. Don't recall any issues with the Atlas locos and the Genesis 2-8-2 is all in the tender. Not impressed with the 2-8-2 headlight, but it wasn't my loco and the owner was happy with it, so win-win!

Start with an easy "plug and play" version with one of the exisiting boards to gain confidence. There are lots of installation posts to follow on the group, and if you run into issues, there are many who will help!

Don't forget to post your installs - they are always beneficial to view.

[KB02]

Start with an easy "plug and play" version with one of the existing boards to gain confidence. There are lots of installation posts to follow on the group, and if you run into issues, there are many who will help!

I agree with this. If you've got the 9 pin plug, the LM3(s) is plug & play. Same for the 21 pin now with the new module.
Adapters can get tricky and annoying and take up unnessasry space. If your locos with the 8 pin plugs need an adapter and space is limited, I might consider hard wiring.

I have a couple locos with the 21 pin plug that I adapted to the 9 pin LM3. The extra wires from the conversion plug make things tight. I've considered buying a couple of the new 21 in modules and converting them over. Not only would it save room, it would give me back the extra light functions I lost with the 9 pin.