can any one help me

I have wired in the red power cable and the brown ground cable

I am using a crossover box from speakers to rca what I used in my old car

I don't no what colour wires or where they are.

I have a problem with my bmw amp which only lets sound out of driver side door speaker will this stop it working when I wire it in to the speakers that don't work.

if some one can help me that would be great thanks