For what it is worth, the powered axle is split electrically to provide two rail operation on some future model. The electrical connection between the powered wheels is through the 2 rail/ 3 rail switch.
I used a Miniatronics 2 pin connector to wire two 44 tonners together. This worked great until all my bad wiring caused everything to fail. One engine has a rub in one direction. The other has a 60 cycle hum. One of the wire nuts most have come off and the exposed wires hit the speaker.