What could be wrong if the low beams and high beams stopped working on a 2000 Toyota Tundra but the bulbs are fine and the daytime running light and the parking lights and blinkers still work?

If the high and low beam headlights stopped working on a 2000 Toyota Tundra, the fault could be with the headlight relay switch. This is a large fuse located in the fuse box on top of the battery.