The wires actually ride on the wheels. So all 4 wheels are connected to the motor. I'm tryint to post pictures but haveing a difficult time. The pics may be stuck in the approval process.
I was able to get the loco on the track and running today. I soldered a solid coppoer wire to the terminals (I think that's what they are called) and bent them to touch the back wheels. That isn't a solution however has the wires are difficult to bend enough to put contunous pressure on the rear wheels. Since it runs with just the back wheels taking up electricity I wonder why the original wires rode on both wheels.
https://farm66.staticflickr.com/65535/52540542615_87169165a5_m.jpg
The reason I believe it is a Varney is the location of something that looks like a pump in front of the cab and the cab is cut back at that location and not square as in the other Docksides I've seen online.
I don't have any 0-4-0s, but did build a Bowser kit for a longtime friend, and, like pretty-well all of my own locomotives, put wheel wiping pick-ups on a piece of copper-clad circuit board...
...the ends of the wires to the motor are visible near the rear.
Here's a similar set-up on an 0-6-0...
...and on the tender, too...
For this one, I used cut-up Kadee centering springs as wipers on the insulated wheels of this loco...
The phosphor-bronze wires used as wipers have good tension to ensure uninterrupted contact from the rails to the motor.
Wayne
Looking at the diagrams in hoseeker, there should be a screw between the drivers into the frame that supports the pickup. Are you sure it's a Varney? Many companies made their version of rhe Docksider. The Mantua model that I have has the flat brass pickups and it is held on by a screw into the frame.
....Paul
https://photos.app.goo.gl/xZqKXqw4vWkUrNxSA
I have an old locomotive that I would like to keep running. The problem I have is the electrical feed from the wheels to the motor. I've looked at several of the Dockside engines and in all the pictues there is a flat piece of copper setting on top of the wheels and screwed into the chasis of the engine. Mine only has thin wires on each side of the engine. Each wire is shapped like a flying "W" with the wings laying on top of the two wheels. I can't figure out how the "W" was attached to the chasis. The body of the engine is a hard plastic.
Apparently this is not a Varney but rather a Revelle loco. I spotted one on ebay and it has the same "W", thin wire, electric feed on both wheels. And if I'm correct the space between the wheel cover and main body shows a plastic piece that holds the "W" in place.