The fog lights on the Chevy Avalanche are supplemental lights used to illuminate the road underneath fog. As the name suggest, these lights are especially useful and effective when it's foggy outside. However, they provide additional lighting at night for improved visibility. Like standard headlights, the fog lights use a high-wattage bulb that, over time, will blow out. When this happens, you'll need to replace the fog light bulb in your Avalanche.
Open the hood and reach down into the engine bay for the fog light assembly. If you cannot reach the fog light assembly from the top you may need to get underneath the truck to reach it. Remove the electrical plug running to the fog light ballast.
Remove the bulb. Unlock the fog light bulb by turning it counterclockwise and pulling it straight out of the assembly.
Slide a new bulb into the fog light assembly. The part number you will need for the new bulb will be located on the ballast or base of the old bulb.
Turn the bulb clockwise to lock it into the fog light housing.
Reconnect the electrical connector to the bulb ballast.
