Mike,
In reading your post at the beginning of this thread you stated your headlight switch "was/is a non fused switch." I don't know about your replacement switch but the original switch had a bi-metallic thermal fuse or circuit breaker in it. That gives you some degree of protection from a short in the headlights, tail lights, gauge lights and dome light. And current use in any of those systems would be indicated by the ammeter.
As an example, let me share something that happened to me when I went for a test drive in the process of restoring my '50 COE. I had replaced the original wiring with a harness from Rhode Island Wiring and used the original head light switch, maintaining 6 volts. Suddenly, the ammeter was gyrating violently from normal slight charge to marked discharge. It would flip from one side of the gauge to the other every second or two. This was the thermal circuit breaker doing its thing, letting excessive current through, overheating, and then breaking the circuit, cooling off and then reconnecting. Of course, I had a 1/2 inch wrench handy to unhook one of the battery cables. I could detect that dreaded smell of burnt wires. It turned out that when I installed the dome light, I had pinched the wire between the light housing and bezel and it took a week or two before the pinch worked its way through the wire insulation. The only casualty was the dome light wire so the circuit breaker protected the rest of the wiring harness. I got to practice replacing the dome light wire through the A pillar again.
Since you have gone to 12 volts you may be interested in redesigning the wiring in order to use accessories and in doing so you may want to use a convenient fuse panel. But the factory wiring was sufficient for the original intended purpose.
Kent
Last edited by Lightholder's Dad; 03/23/2018 3:07 PM. Reason: clarification
