I posted this question on Railwire and on the Soundtraxx Yahoo group and thought I would try here too. I have several Intermountain Cab Forwards and one of them was a victim of an early attempt to wire in a Tsunami decoder. I worked on this engine when Intermountain first released the loco and for reasons I no longer remember, I removed the motherboard from the tender and wired the decoder directly to the loco while doing this. Everything works correctly (except one thing), it moves forwards and backwards and has the correct sound for an articulated engine. It has several hours of run time. When I finished the engine I had one wire in the loco not terminated on the decoder and I believe this is why the number boards do not light up. I recently purchased a couple Tsunami2 TSU 1100's and on that decoder I see a green lead (for fx3) and a brown lead (for fx4). So I replaced the original Tsunami with the new one and connected the loose wire, after adding a resistor, to the brown lead. The number boards still do not light up so I am asking if there are one or more CV's I need to set to enable fx4 and turn on the lights? The other option is to connect them to the yellow wire (I did not install a backup light) but then I need to program it to be facing forward and on all the time.
Marty, I am, by no means, an expert and I have zero experience with the Tsunami ( new ones). You mention connecting a brown lead (Fx4) with a resistor. Typically a decoder has a blue common wire that also connects to the other LED lead. You have not mentioned a blue wire. If I remember correctly my AC-12 from very first run had all black wires in the loco and tender so I am not sure how you can identify a common (blue) lead. Please, research this a little before making any connections. Just food for thought. Always have fun, Carl
When I first started this many years ago I had contacted Intermountain asking for a pinout of their connector because all the leads from the engine are black. They replied with that pinout and a comment that no one had ever asked for that before. I cannot find that diagram again so now working in the dark. I had installed an older Soundtraxx decoder then and replaced it last week with a new Tsunami2 TSU 1100. When I removed the old decoder I left the color traces still connected to the black wires from the engine so I knew what went where. I knew they were right because the engine had several hours of operation but the number boards never did light. One of the traces I left connected was brown. The loco still runs and the sound is better but the number boards are still dark. The new decoder has a brown lead labeled fx4 so I connected my old brown lead to it and the headlight still works correctly. I asked this question on the Soundtraxx forum also and the answer I got is that there are several hoops to jump through to get an output from fx4. Since I did not install a backup light that left me with the yellow lead unused so I moved my connection from the brown lead to the yellow lead. Now the number boards do light up! But only in reverse. So I need to find the CVs that make the yellow lead face forward and be on all the time.
