I was in the bilge the other day and glanced at the ground strap/bar at the back of the bilge. It has 2 large posts, one at either end, then smaller posts in the middle. Lots of black wires going to it. One large black wire went to 1 large post then to (as far as I could tell) the port engine. But the other large post did not have anything. It made me wonder, should there be a similar large black wire from the starboard engine to the strap/bar?