Fog lights on Ford F-150 are wide beam, low-mounted headlights, which are primarily intended for use in poor visibility due to fog or precipitation.
Fog lights can be turned on by pressing the button on the lights control switch. But when the lighting control is in the Autolamps position, you cannot switch the fog lamps on unless the headlamps are on.
Press the button on lights control switch rotary dial to turn on fog lights.
Note: The brightness of the daytime running lamps may decrease when the front fog lamps are switched on.