sorry if this has already posted but i am installing a battery isolator on a dual battery setup...house, starter...i get how to wire the isolator other than the excitation terminal from the alternator.(is this even needed)...im guessing i need to run another small gauge from excitation terminal to isolator...but what do i do with the existing wire? also can i share the ground for both batterys and connect the ground terminals of the battery together?also would i hook up the onboard charger to the isolator or do i need to charge them seperatly? wow i think i have more questions than answers! thanks in advance...jay...