Are you running a Chevrolet or a GMC chassis? Chevy 6-volt systems used negative ground electrics, GMC used the positive ground system like most big trucks did. Look at the battery posts, not the color of the cables. If the larger diameter of the two posts is connected to the frame, the system has been set up as (+) ground. That may, or may not be right.
Does the rig have a generator or an alternator? If it's set up for an alternator, it needs to be negative ground, as there are very few (+) grounded alternators. A generator can be polarized either way, but I'd still reccomend going with negative as the ground polarity. It sounds like you need to spend a considerable amount of time learning about electrical systems, or find someone to help you who knows what he's doing. It only took me 10 years or so of working on these systems before I got really comfortable around them, and our family shop was the best one in Middle Tennessee where electrical work was concerned.
Jerry
Last edited by Hotrod Lincoln; 10/23/2010 4:33 AM.
