If you look closely at the stock decoder board you will see....
"R" - Right pickup
"M+" - Motor Positive
"L+" - Light Positive
"L-" - Light Negative
"M-" - Motor Negative
"L" - Left Pickup
Or something similar on the pin outs that the wires connect too. They may be marked on the bottom of the stock decoder.
"R" - Right pickup
"M+" - Motor Positive
"L+" - Light Positive
"L-" - Light Negative
"M-" - Motor Negative
"L" - Left Pickup
Or something similar on the pin outs that the wires connect too. They may be marked on the bottom of the stock decoder.