We have had several questions on grounds lately. Poor grounds account for a majority of the electrical problems that involve several circuits When you check a ground dont just look at it take it apart and clean all surfaces until they are bare metal or do a voltage drop test( more on this later)A shot of clear lacquer over the connection is also a good idea or clear spray paint I aslo do this to the battery connections it is not as messy as battery protector and I think it covers better