2007 GMC Sierra 1500 Pickup Owner's Manual - Page 225

Fog Lamps If your vehicle has fog lamps, use them for better vision in foggy or misty conditions. The fog lamp button is located on the left side of the instrument panel. Remember, fog lamps alone will not give off as much light as the headlamps. Never use the fog lamps in the dark without turning on the headlamps. The fog lamps will go off whenever the high-beam headlamps come on. When the high beams go off, the fog lamps will come on again. The fog lamps will be cancelled after the ignition is turned off. If you still want to use the fog lamps after you restart the vehicle, you will need to press the fog lamp button again. Some localities have laws that require the headlamps to be on along with the fog lamps. The parking lamps and/or low-beam headlamps must be on for the fog lamps to work. Press the button to turn the fog lamps on or off. An indicator light will glow in the button when the fog lamps are on. 225