In my '98 lumina I still have factory speakers installed. They still work, but I want to wire a sub box in place of the rear speakers. I looked at the speaker wires to find the + and -, but they were not labeled that simply. On the left speaker, there is a brown wire labeled A and a yellow wire labeled B. On the right speaker, there is a light blue wire labeled A and a dark blue wire labeled B. Does anyone know which wires go where? Also, I know some subs require power, I need to know where i can take the power from. There only seems to be the power line for the trunk light, and tapping into that doesn't seem like there would be enough voltage. Any help is appreciated.