Harley-Davidson FLHTK Ultra Limited headlight bulbs utilize a 9003 size for both high and low beam functions. The replacement chart covers 2010 through 2013 production years with corresponding bulb specifications.
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 bulb type specified across all listed positions and model years for the Harley-Davidson FLHTK Ultra Limited, covering both high beam and low beam headlight applications from 2010-2013.
The 9003 is a dual-filament halogen bulb, meaning a single bulb unit contains two separate filaments: one rated at 60 watts for high beam output and one rated at 55 watts for low beam output.
The 9003 operates on a 12-volt electrical system, which is standard for motorcycle applications in this class.
The 9003 uses a P43t base, a bayonet-style mount with a 43mm collar. This base type is a defining factor in physical fitment and is not interchangeable with bulbs using different base configurations, even if wattage or voltage ratings are otherwise similar.
The 9003 is an ANSI-standardized bulb designation applicable in the United States and Canada. It is technically equivalent to the ECE-designated H4 bulb used in international markets, sharing the same physical and electrical characteristics under a different regional naming convention.
Because both the high beam and low beam positions on the FLHTK Ultra Limited share the same 9003 specification for 2010-2013, a single bulb type serves the entire headlight assembly rather than requiring separate bulbs for each function.