I have a '67 715 in which the headlights will only stay on for 3 minutes. Then what I would call a breaker heats up, cuts the power, and the headlights go out. After a few mintues the headlights will work again. Does anyone know where I can find this breaker to replace it with a fuse and how it can be identified where it's at? Or is it some other problem? I don't want to think it's the wiring harness.