HID Xenon Ballast Compatible With 02-03 Audi A4

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.

Before purchase, we advise you to verify your year, make, and model by referencing the VIN tag by your driver side door to make sure you are starting with accurate info. If you have any questions, please contact us before placing an order, and we will help you determine the correct parts for your vehicle.

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.