Do all electronics go out or just the headlights/dashlights. Does the radio still play? If it's just the lights and the rheostat turned to brighter makes it get better/stop, it sounds like the headlight switch. Don't know about the 80's style F-150 but hopefully it's a push/pull switch on the dash. A little easier to change than one of the rotating type switches built into the turn signal or some other lever on the column.

CW

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