Driver Passenger Tail Light Set For 16-18 BMW 3 Series 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 old lights probably had moisture or condensation in them too, but the older, dulled and oxidized lens makes moisture less noticeable. Now that you have those new clear lights on your nice car, all of sudden you’re really looking at them, which is completely normal. Without going into too much detail, It's a fact that condensation happens just about anywhere. If there's a temperature difference between the inside and outside of the lens, moisture will occasionally develop, and, since your Halogen headlight bulbs put out some heat, the inside of the headlight is full of warm air while the outside is cooler. This is sort of like how the front window on your car can fog up and you have to turn on the defroster vent to clear it all away: The condensation in your headlights will usually dissipate after the headlights are turned on, as the heat of the lights evaporates the moisture. Your high beams will usually produce more heat to clear any condensation more quickly.

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.