Neat, not seen that colourway before. Looks like a double pin socket on the rear cab wall.
Rear socket will be track-power..
Thanks JonRik this is LgB 2060 or 20620, if you can find the break down diagram for this it should help you. Other LGB numbers of these as variants are 21620, 21625, 22620, 70500 and 23620.
I connected the socket to the remote control system, the locomotive didn't run smoothly. It seems the electricity is being modulated through the internal circuit board. And then to test whether that socket has a direct connection to the motor, I inserted a direct line from an LGB power line to the socket, the motor didn't run and the locomotive has very dim light. It may explain that the socket does not directly link to the motor but rather modulated through a circuit board. It could be used for lights but not for powering the locomotive.
General views were that it is not good practice to feed the loco through those 2 plugs.Neat, not seen that colourway before. Looks like a double pin socket on the rear cab wall.