Got an 08 50HP mercury 4 stroke. Apparently I overwhelmed the ground wire with the addition of some lights on my boat. Anyway they quit working for lack of a ground to the boat. I found that the engine is no longer grounded to the boat. The engine runs ok and is grounded by the starter cable but there should be a ground connection from the engine to the boat. Any ideas where I might look to repair or replace the faulty wire. I have since grounded the lights directly to the battery since the hull is no longer grounded.