I have a 72 grande and for some reason when i have my headlights on for probably 20-30 minutes they will suddenly turn of for a little bit then come back on and then it keeps doing it and i have no idea why any suggestions?

 

The high low beam switch may have a loose plug or is going bad or it could be the main light switch.

 

Check your headlight plugs for poor connections. Next, check the headlight switch itself. If you can find no problems, you may have a short, or you may need to replace the switch. I believe the switch has a built-in circuit breaker. An intermittent short would trip the breaker intermittently.

 

i asume you are running halogens?? probably just the switch i had to replace it on my 72

 

My bet would be the switch. Had it happen twice, each of which was the switch.