help locating the wiper from the engine wheels

[MisterBeasley]

A wiper is typically at the very top of the wheel. Look for a thin flat metal strip that may be mounted between two wheels and extend out to both of them. There will likely be one on each side of the engine.

[pontoonman]

I have bought at an estate sale a steam engine, Broadway Limited Mikado 2 4 2
but cannot get power from the drive wheels.
I have power from the tender and have run the engine using a jumber wire to the positive side of the can motor using the tender as ground but cannot get power from the wheels (right side) when i put on tracks.
Where to I find the wiper that makes contact with wheels.

thanks