Hi Guys/Gals: Here's a strange electrical failure that I've never seen before. About a year ago, I began having some issues with the hi beam/low beam selection on the headlights on my very stock 1974 Duster. All wiring is factory original, but the foot operated dimmer switch was replaced two years ago with a new Echlin part (DS-112 from NAPA). I began to notice a fault that would come and go. When driving at night in high beam, the headlights would go out. When I shifted to low beam, the headlights came back on in low beam. A week ago, the high beam lights went out again while driving at night. Shifting to low beam didn't help - the lights were still out. Then they began to flicker, so I pulled over. As I pulled over, the entire car went dead. Absolutely nothing. I changed out the ballast resistor, but that didn't help. About two minutes later, I noticed that the interior lights had come back on. So I tried starting the car and it worked. As long as I drove in parking lamp only (no headlights), everything was fine. So what's going on? I learned that the headlights are not protected by a fuse, but by a circuit breaker. Is it possible that something shorted internally in the dimmer switch and opened up this circuit breaker? I suspect that once the breaker cooled down, that it closed by itself regaining electrical control of the car. If so, why would an open headlight CB kill an entire car? I replaced the dimmer switch with a new Echlin one and everything works perfectly now. Any ideas? Where is this circuit breaker located? Have I damaged anything in my electrical system? Ideas?
