Installing Fog Lights on a Base Model 1999 GMC Sierra 1500 graph.org

To begin the fog light installation, choose a kit designed for GMT400-platform trucks (1999 was a transition year, but the Sierra classic body style shares components with late 1990s models). Universal LED fog light kits with a 3- to 4-inch round or rectangular housing work well. You will also need a wiring harness with a relay, fuse, switch, and sufficient 14-gauge wire. Start by removing the lower bumper valance or marking the blank plastic inserts where the fog lights will mount. Use a hole saw or Dremel tool to cut openings that match your lights, then secure the housings with the included brackets. For a clean, factory look, position them symmetrically about 12 to 18 inches inboard from each corner.