My lights come on fine in my 1941 Ford but after about 10-15 minutes all lights go off. I wait about 5 minutes and pull the switch and the come on again but go out again after another 10-15 minutes. Like something gets hot and works again when it cools. Does someone have suggestions. Thanks.
I would suspect a bad ground connection, or a chaffed positive wire shorting to ground.
It sounds like your lights are hooked up to a circuit breaker, instead of a fuse. They could also be hooked up to a universal relay that is failing when hot. Most of the time these relays just fail though.
The headlamp switch has a circuit breaker built into it that will trip if the load gets too great. You might be able to get away with just replacing the headlamp switch, but I suspect there is another reason the breaker is tripping. Check all your connections and grounds. Also consider rewiring your headlamps using relays. It will unload your system and you will have much brighter headlamps to boot.