"If you are using it in an OB
"If you are using it in an OB application, the field leads are not used. Just be sure to bring the motor down to idle prior to switching batteries. The instructions may require you to turn off the engine, but the OB puts out so little amperage at idle it will not hurt to switch with it running.
You only need three terminals: B(+) #1, B(+) #2 and common.
Everything currently hooked to your current battery (+) will connect to the common, with the exception of the auto bilge switch and any CO monitors (if applicable).
These wires should connect directly to the B(+) to eliminate the possibility of turning them off.
West Marine usually has diagrams available on their site if you need a printed version.
Rick"