Originally Posted by greggoudy
I attached the cable to the wing nut that was holding the cables on the positive post on the single battery. Now not only did my engine start, but I had tail lights.
It appears you had it right, for that moment.
I donít know how your electrical system is laid out.
If the grounds arenít tied to a common point...youíll have to keep the positive on the same circuit as the negative for the lights. If you have any 6-v batteries...you have to make sure the positive terminal you chose isnít giving you only 6v vs 12v. Avoid the positive that is series tied to the other battery in the pairís negative terminal. That is IF you have two 6v batteries joined to make a 12v system.