Different colors on each side.
Power, ground and signal, not sure without looking which is which.
You MIGHT be better off coming from the tender, especially if you have already inverted the signal in the tender for your choice of sound systems.
There are more wires that you really need from engine to tender (I remove 5 of them), so choose what you need.
You radio/battery on this one?
Use the power pickup wires.
Remove them from the plug on the lower firebox board and connect to the smoke unit, and WHACK them off the Ames Super Socket, parallel to the chuff inputs to your sound card.