Battery Drain on 2008 Toyota Tundra

If I leave my 2008 Toyota Tundra parked for more than three days, the battery is dead. Mechanic told me that there is a draw on battery, but doesn't know where. Anyone else have this problem and how to fix it.

1 answer
The battery can become drained if your truck has the auto-shutoff headlights feature, and you leave the headlight switch in the "on" position and rely on the auto-off feature to shut them off. The relay that shuts off the headlights draws power from the battery.