The Yamaha XL540 VLX uses a 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers 1985 to 1990 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Yamaha XL540 VLX uses the 9003 bulb for both high beam and low beam headlight positions across the 1985-1990 model years.
The 9003 is a dual-filament halogen bulb, meaning a single bulb unit contains two separate filaments to serve both the high and low beam functions within one housing.
The 9003 operates at 12 volts, with the high beam filament rated at 60 watts and the low beam filament rated at 55 watts.
The 9003 uses a P43t base, which is a bayonet-style mount with a 43mm flange. This base type determines physical fitment and is not interchangeable with bulbs carrying different base designations.
The 9003 is defined under ANSI standards and is recognized in both the United States and Canada under that designation.
Because the same bulb size is specified for both the high beam and low beam positions, the XL540 VLX headlight assembly relies on the dual-filament design of the 9003 rather than separate single-filament bulbs for each function.
The 9003 shares its physical and electrical characteristics with the H4 bulb, which is the international designation for the same lamp type. However, fitment compatibility between 9003 and H4 labeled bulbs depends on the specific base and housing tolerances of the application.