I see white specks on the boat. The common ground your talking about, do i put the electrical tester on it and if so what goes to what like put red to neg on the battery and the black to the hull. I am not much for electrical testing or work. I called the dealer from which it came and they said sounds like a bad anode. Alot of the wires are buried and tied up to every thing its a pro team 185 tracker 2002. Thanks for the help