Good luck. You would have the best luck contacting the manufacturer but I'd wager they don't even have one. Boats electrics are woefully ill-documented. Here's a generic wiring diagram however:
I have a nice diagram for 20' or less boats; it's to large a file to post as an attachment here. If you will PM me I'll e-mail it to you. I can also guide you to an elegant larger boat diagram at the same time.
