I am trying to figure out the 7 solder connections on the printed circuit board on the dcc decoder. They are labeled M+, M-, R, L, L+, 1- and 2-. Some of these are obvious such as the M+ and M- for the motor. I am thinking that the R and L are the electrical pickups from the trucks. Not sure on the L+ and the 1- and 2- but two have to be for the front and rear lights.
R: Right Rail
L: Left Rail
M+: Motor Brush Connected to Right Rail
M-: Motor Brush Connected to Left Rail
L+: Light Positive
L-: Light Negative
Source: https://www.bachmanntrains.com/home-usa/board/index.php?topic=34392.0;wap2