Why Do BMW Xenon Headlights Stop Working? (And How to Fix Them)
Image: BMW X6 Series Xenon Headlight for sale at MT Auto Parts for £284.99 One headlight goes out. You replace the bulb, and it still does not work. Or one side flickers on startup and then cuts off. Or both headlights are working, but one is noticeably dimmer than the other and has a slightly different colour. These are the typical presentations of BMW xenon headlight faults, and in most cases the bulb is not the problem. BMW xenon headlights are a three-component system. Understanding which of the three has failed saves money and avoids replacing parts that were working fine. How BMW Xenon Headlights Work Unlike a halogen bulb that simply glows when current passes through a filament, a xenon bulb creates an arc between two electrodes inside a gas-filled capsule. To start that arc, the system generates a pulse of around 25,000 volts at ignition, then maintains the arc at a lower operating voltage once lit. Three components make this happen. The ballast converts the car's 12-volt ...