The Buell S1 Lightning headlight bulb uses a 9003 size for both high beam and low beam functions. The replacement chart covers vehicle production spanning 1996 to 1998.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9003 bulb is the sole type specified across all headlight positions for the Buell S1 Lightning, covering model years 1996-1998.
The 9003 is a dual-filament halogen bulb, meaning a single bulb unit contains separate filaments for both high and low beam operation, which accounts for its use in both headlight positions on this motorcycle.
The bulb operates on a 12-volt electrical system and carries a wattage rating of 60W on the high beam filament and 55W on the low beam filament.
The 9003 uses a P43t base, a bayonet-style mount with a 43mm collar, which physically determines housing compatibility and is not interchangeable with bulbs carrying different base types.
The 9003 designation follows the ANSI standard used in the United States and Canada. It is electrically and functionally equivalent to the European H4 bulb, though the two designations reflect different regional certification standards and may carry minor physical differences that affect fitment.