Hi,

I have a similar set, the 42160. You need to separately bring the two polarities (rail and center) to the light bar. For that you need in each wagon a 72021. That brings the rails up in each wagon. In addition to that you need in at least one wagon a pickup shoe, probably 73406 (or 73405, or 73404, see what fits, don't remember exactly which one I picked).

I prefer to install a single pickup shoe and use the current conducting couplers from 72021 to bring this polarity to the rest of the wagons. This keeps the noise at a lower level.

As for the interior lights, ESU 50708 is really great.

Cheers,

.costin