primary wiring?
I don't recall what kind of engine an OD 20 has... But, assuming you are talking about primary wires for powering everything...Battery wires normally are red (positive) and black (negative/ground). It is a bit of a mystery as to why you have a white primary wire. I'd trace the wire to see where it goes. If it is connected to a grounding point (like a bolt on the engine block) it is the negative terminal. If it runs to a device, like a switch, then it is the positive... But, before I started down that path, I'd go to a boating store and buy a book on boat and boat engine maintenance. Good luck!
