Driver Passenger Tail Light Set For 04-07 GMC Sierra 1500 & Classic CAPA Certified

HID stands for "High Intensity Discharge". These bulbs use an electric arc rather than the glowing filament in a Halogen bulb. HID headlamp bulbs do not run on low-voltage DC current like a Halogen Bulb, so they require a ballast, which controls and regulates the flow of current. This ballast will require an ignitor to light the bulb. This is either integrated directly into the bulb or as a separate unit which is occasionally part of the ballast, similar to fluorescent bulbs in your home. In a vehicle, HID bulbs tend to be much more expensive to replace than a Halogen bulb.

Your headlights will be warm to the touch from the heat generated by the bulb. The filament inside of a headlight bulb can reach temperatures of over 4000º F while the temperature of the glass surface of the bulb can exceed 150º F. This means that heat will naturally radiate to the exterior surface of your headlights. This intense heat is also what will help your headlights remain condensation and moisture free. However, to prevent burns or other injuries, be sure to let bulbs and headlight assemblies cool completely after use before handling.

You may well have to adjust the headlights after installation. If it's possible, when you take the old assembly out, you should match up the new adjusters with the old ones. Adjust the new light as close to that on the old units as you can. That way, any adjustments you have to make on the car once they are installed will be minimal. Our headlight assemblies have the same or improved adjusters as the stock units, and there are many videos on Youtube on how to adjust lighting. Check your owners manual too, since not all vehicles are adjusted the same way. Finally, when adjusting, make sure your car is level, with a full tank of gas.