[rheavn]

I had the same thing occur in a 70's vintage motorhome many years ago. That motorhome used a Ford headlight switch that had a circuit breaker built in. When the lights went out it was caused by the failure of the internal circuit breaker. Not sure if your switch is designed this way, but something to check. I relate to your experience very well as it was quite shocking when all of a sudden the headlights quit--very dark, very fast!