If you want to get a copy of a general boat wiring schematic follow the link below & it'll give ya the standard wiring for American boats.

http://www.brokeboats.com/biacolors.html

This should work for most or all boats assembled & set-up in the US.

Boat wiring is just like wiring in your home or tow trailer, it should be the same as the rest (a standard) if it was properly set-up to begin with.

I hope this helps ya'll out.

Good luck & happy boatin'