I have a couple of older Kato units, a BN SD9 and this BNSF SD45 that I want to keep in my fleet and possibly upgrade them to DCC, When you pull the shell off, they both look like this. Basically a light board at each end. What decoders have you all used in this situation and which do you recommend? No sound and about all I'd really need for these is Lights, Direction, and Speed controls. It may be more than I want to tackle but worth investigating. I saw TCS has a Split board CN model decoder that looks like it might wok and I thought I saw Digitrax had one that was just the board for one end and I guess would wire to the lightboard at the other end. And either one would have to be wired to the motor contacts.
I have used the TSC CN decoders before. I usually mill out a notch in the top of the frame halves to run the connecting wires between the two boards that replace the stock light boards but I guess it would be possible to cram the wires under the shell side by side without doing that. I also mill notches down to the motor contacts.
On the SD9, I have installed the TCS CN-GP with some minor frame modifications. I made a blog post on this installation, here's the link. N Scale DCC Decoder Installs: TCS CN-GP in an Atlas SD9 (n-scale-dcc.blogspot.com) I've also used the same decoder on an SD45 but don't have any documentation on that installation.
I have a friend who has done several older Kato SD45s and he prefers the TCS CN-GP. He just installed a TCS CN in an Atlas RS1 for me. He said on my RS, the frame seam was large enough to run the wires down, so he did no milling at all. If I remember when I was buying the decoder, the CN is a 2 function and the CN-GP is a 3 function.......other than that they are interchangable.
It isn't that hard to use..... https://1fatgmc.com/RailRoad/Decoder-1/page-5.html .... the lightboards for track pickup and use another small (very small) wired decoder under the light board..... https://1fatgmc.com/RailRoad/Decoder-1/page-28.html .... like a LokPilot that is shown above with more functions if one wants to add more lighting now or in the future. I still have a number of Digitrax decoders left but for anything I want to really run well I'm installing the LokPilots. Also they will consist better together or with the LokSound sound decoders I've installed. I think TCS was running a special on the CN for $30 about the same as a LokPilot and if not on special a lot more. Sumner
I've done 3 installs on club members' locos. Don't remember if they were CN or CN-GP but in all cases I was able to route all the wires without milling channels.
I used TCS CN-GP on the SD40s and Atlas GP units and aolder Kato UXX engines. Now changing to ESU LokSound. Takes a bit of machining to fit in the speaker and a 58923 decoder. I have two spare CN-GP units available that were pulled out of service. Send me a PM if you are interested.
Here is a conversion from the 2 PCB light boards (or TCS CN-GP) to an ECS LokSound 58923.. Takes a little bit of machining. You can do it with a couple of files also. The lights just slide into the plastic lenses on each end, and hold with the wire tension- works well, and easy to take apart.