2008 GMC Yukon Owner's Manual - Page 193

Fog Lamps If your vehicle has fog lamps, the button is located on the instrument panel to the left of the steering column and below the dome lamp override button. The ignition must be in RUN and the parking lamps must be on for the fog lamps to work. To turn the fog lamps on, press the fog lamps button. A light comes on in the instrument panel cluster to let you know that the fog lamps are on. Press the button again to turn the fog lamps off. When the fog lamps are turned on, the low-beam headlamps automatically turn on. The fog lamps turn off while you change to high-beam headlamps. When the high-beam headlamps go off, the fog lamps will come on again. Fog lamps should only be used in foggy conditions since they could be distracting to oncoming drivers in clear weather conditions. Some localities have laws that require the headlamps to be on along with the fog lamps. Auxiliary Roof Mounted Lamp If your vehicle has this feature, this button includes wiring provisions for a dealer or a qualified service center to install an auxiliary roof lamp. This button is located on the overhead console. - (Fog Lamps): When the wiring is connected to an auxiliary roof mounted lamp, pressing the bottom of the button will activate the lamp and illuminate an indicator light at the bottom of this button. Pressing the top of the button will turn off the roof mounted lamp and indicator. The emergency roof lamp circuit is fused at 30 amps, so the total current draw of the attached lamps should be less than this value. The attachment points for the roof lamp circuits are two blunt cut wires located above the overhead console, a dark green switched power wire and a black ground wire. 3-19