Upgrading Your 2004 GMC Sierra to DOT-Certified Headlight Assemblies luxevolume.com
Replacing headlight assemblies on a 2004 Sierra is a straightforward, tool-free process that takes about 15 minutes per side . Open the hood and locate the two vertical anchor pins securing each headlight assembly. Twist these pins a quarter-turn and pull them straight up to release them. The entire headlight assembly then slides forward out of the truck. Behind the assembly, disconnect the wiring harnesses for the low beam, high beam, turn signal, and side marker bulbs .
Important note: When handling new bulbs, avoid touching the glass surface with your fingers. The natural oils from your skin create hot spots that cause premature bulb failure. If you accidentally touch a bulb, clean it thoroughly with rubbing alcohol and a soft cloth before installation .