Headlight's blinking

I have a 1996 GMC Jimmy, 146,000+ miles. When the lights are used, they start to blink on and off, or should I say headlight's then to daytime running lights? I turn them off, and just have the daytime running lights on, and then they work for a bit, then may start blinking again. Any ideas?

probably the switch i think it has a circuit breaker built into it like the trucks. might also be a bad conection somewhere. turn the lights on and start wiggiling wires in the circuit. check the ground conections too i don't remember where they are located but a chiltons/ haynes manual should point you in the right direction.

Sounds a bit like a ground issue.... Turn on the lights and start wiggling the wires at the lights themselves and see if you can make it do it that way.