I have a question, I have a '79 F-250 and for some reason the lights will shut off and turn back on whenever they feel like it after the truck warms up but fine when cold, it's not more than a couple seconds but not driveable on road as is....please help!!!

 

If you are referring to the headlights, it sounds as if the circuit breaker on the switch is cutting out. Common failure for the light switch. Best fix is to replace the switch.

After you replace the switch, go to the tech section and check out the brighter brights article. That modification will reduce the amount of current running through the switch and may prevent a future occurrence.

 

could be the headlight switch, or the dimmer switch....if it happens again try clicking the highbeam switch and see if it changes, if so the replace it....

 

I replaced the headlight switch which helped, but found the problem was the dimmer on the floor, it had a hole corroded in the die cast case, it got dirty and damp and caused the headlight c/b to trip..............replaced it and did the "brighter whites" conversion.................big difference and not too much cost