As I am going thru my Comp this winter and working on different projects, I notice a ground wire. You ask how do you know its a ground wire. Well its black which is traditionally used as a ground wire and it also happens to be connected to the ground screw on the fuel sending unit before the wire goes into the main harness etc. So, it looks like it should be attached to one of the screws on the fuel nozzle so as to ground that when you are fueling. Can anyone verify this? Other than that I have no idea where it would attach based on its location lying in my boat.