Lighting Systems

Halogen bulbs use a tungsten filament inside a glass capsule filled with halogen gas. They are inexpensive and easy to replace but produce the least light output of the three modern headlight types. When replacing halogen bulbs, never touch the glass with bare fingers — the oils from your skin create a hot spot on the glass that causes premature failure. Handle by the base only or wear clean gloves.

HID headlights — also called xenon headlights — use an electric arc inside a gas-filled capsule instead of a filament. They produce significantly more light than halogen. The system requires a ballast module that generates approximately 25,000 volts to strike the initial arc and then regulates it at approximately 85 volts during operation. A flickering or non-starting HID headlight is usually a failing ballast or igniter, not the bulb. Always replace the bulb and ballast as a diagnostic pair if the initial replacement does not resolve the concern.

LED headlights use light-emitting diodes that produce light through semiconductor physics rather than heat or arc. They draw less power, produce less heat directed forward, last significantly longer than halogen or HID, and allow complex adaptive beam patterns. However, LEDs generate heat at the back of the assembly that must be managed by heat sinks or small cooling fans. A failed cooling fan causes the LED module to overheat and shut down or dim. LED headlight assemblies are typically not bulb-serviceable — the entire assembly is replaced, which makes them significantly more expensive to repair.