For the past couple of weeks I have been battling an electrical wiring issue which blows the 15 amp headlight circuit. I mentioned to my son that I was using 15 amps fuses by the box during the troubleshooting. He said he had seen a mechanic who had fashioned together a homemade device which consisted of a 15 amp, 12 volt self resetting circuit breaker that he plugged into the fuse box. By using this gizmo he did not have to keep replacing the burnt out fuses while he was trying to find the short.
Anybody out there have such a shop made gizmo? If so, what was involved in making it?

 

Older Harleys like my 1990 model don't have fuses, just a few thermal circuit breakers. I would guess you can get one from any auto parts store. Mine have screw terminals to which you could attach short wires to jam in the fuse holder. It will cut power when it gets hot, then reconnect once it cools down.

However if you know which fuse is blowing you are halfway to finding the problem! This sort of electrical problem is often actually mechanical - in other words a worn wire, or some other physical damage. Have you checked or changed the headlight bulb?

 

Rather than faultfinding with the power on, try using an ohmmeter. A blown 15amp sounds like a dead short to ground.

 

Yes, I know which fuse is blowing. I have used about a dozen or so fuses up to this point. I can not find any wire which is obviously broken or chaffed. I have even resorted to using a magnifying glass to visually inspect the wires looking for a "smudge" or burn through mark, all to no avail. I have replaced the head light bulb as well as the receptacle that the bulb plugs into. Yesterday I replaced the headlight switch. Still, no joy. I need to come up with some sort of a self resetting circuit breaker that I can plug into the fuse block to keep from replacing so many of those little 15 amp mini fuses until I find the problem.