Aluminum. Specifically 2000-, 6000-, and 7000-series aluminum alloys. There is also titanium and stainless steel, where high strength takes precedence over light weight.
Start with BATTERY CABLES and BODY GROUNDS. If you have loose connections, it is extremely difficult to correctly diagnose intermittent problems. If you or one of your friends know of a good mechanic, ask if they would look at it to give you some ideas. STAY AWAY FROM DEALERSHIPS! Most of us need the make, year and model to help you more.
Because of safety concerns, headlights don't generally have fuses, but rather circuit breakers that will turn them off to avoid overheating and possible fire, but then will reset so you aren't driving in the dark, which would be unsafe. You have a short somewhere in the system, find it and correct it.
It is impossible to answer this question without actually looking at the vehcile. It sounds like it could be the wiring, but like I said.
