I need to add some sound to the inside of the TJ. For now, I'm throwing some old 6x9 boxes in the back and splicing into the factory wiring at the rollbar. I need to know which wires are which. There are six wires going up the rollbar to the soundbar, two being for the dome light I assume. Which wire is the Left Positive.....and so on? I can't find a freakin manual anywhere!!