Left Driver Side Headlight For 03-04 Mercury Grand Marquis Production From 8-7-03; 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.

Replacing stock Halogen headlights with HIDs would require some modifications, especially where the wiring is concerned. While the lamp can sometimes fit into the opening on the front of the vehicle, your stock lamps will use different bulbs, sockets, fuses, relays, and wiring than most HID bulbs. You may want to check with your local mechanic for advice if you have never attempted this type of conversion before.

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.