I have a set of Bachmann F7's that I used an NCE HO decoder to run THREE off of one. The decoder is housed in the B unit. I used six wires going in each direction to get motor power to the adjacent A unit, and to conduct track power back to the B unit. the last set of wires carries the headlight power. The wires are black and I think 30 gauge wire, and hang in such a way that they appear to be MU hoses. I was simply careful to not mix up which wire went where. I also used 3D printed drawbars to hold the units together and bring the spacing much closer. I believe these are the most recent version of F unit, as I bought the parts for the B straight from Bachmann.
