The 2203T tender would normally have two connections to the locomotive. One would run from the accessory shoe on the rear tender truck to the locomotive where it would be connected to the front coupler. When the accessory shoe was energized, both the front coupler on the locomotive and rear coupler on the tender would open. The other wire would connect to a power source In the locomotive's cab and supply power to the tender to run the back up light and, on the B version, the bell.
The coupler connection is of no use on a Scout locomotive and should be stored or removed. You could energize the back up light with one roller on the rear truck, but the light will go out momentary ever time the tender passes over a switch, crossing, or uncoupling track. A better arrangement would be to connect the power wire from the tender to something on the Scout motor that is connect to the two current collectors.
Normally on the 2203T back up light board there are two conductive straps. One connects the lamp shell to the lamp board bracket, which grounds the socket. The other strap, under the fiber board, connects the center lamp terminal to an eyelet on the side of the board. This is where the power wire should be connected to light the lamp.
