You can call or email basscat for a wiring diagram I think. But, most boats will have electronics and accessories hooked to the cranking battery and only the trolling motor hooked to the other batteries. The cranking battery is re-charged while running the big motor, but the other batteries are not (without special set-ups). You probably wouldnt want your electronics, pumps, lights, etc drawing power from your trolling batteries all day. Hope that helps. KentKent Charles 2002 Pantera Classic & 200 Yamaha VMax