You can install brass wipers that rub on the smooth backs of
the wheels. The best power pickup would have all 4 wheels
on each side in use. Then flexible wires soldered to
the wipers thru a hole in the floor of the car to the
A second, less dependable method. is to install a brass
wiper that rubs on the axles. This system has
less friction than the all wheel type, but is more
likely to provide less dependable power since one
truck picks up right rail, and other picks up left rail.
You can make your own wipers by cutting them from
a small sheet of springy brass.
Those Central valley trucks are great. I wish they made them in N-scale!
You can use track power through those trucks If you wish, but it seems like a lot of trouble to get lights that don't stay on except when the train is moving. That won't be the case if you are using DCC since it has constant power on the rails. I prefer battery power lighting using LEDs. Small disc type batteries are available in 3 volts DC. That will light an LED. Two such batteries, in series with a current limiting resistor will light a car full of LEDs. The lights can be turned on or off with a small concealed switch. One idea uses a magnetic reed switch mounted to the inside of the car floor. A small magnet, painted flat black, and disguised as a bit of under the car equipment, will turn the lights on when it is stuck to the bottom of the car directly below the switch. Another scheme is to use a vent, or other detail part on top of the car. The vent needs to be able to be rotated. Rotating the vent one way moves a rod that triggers a Micro-switch inside the car to turn the lights on.