Big Dog Bulldog high beam and low beam headlight bulbs both utilize a 9003 bulb size. The replacement chart covers vehicle production spanning 2001 to 2011.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Big Dog Bulldog uses the 9003 bulb for both high beam and low beam headlights across all listed model years from 2001-2011.
The 9003 is a dual-filament halogen bulb, meaning a single bulb unit contains two separate filaments to serve both high and low beam functions within one housing.
The 9003 operates at 12 volts 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, which is a bayonet-style mount with a 43mm flange used to secure and align the bulb within the headlight assembly.
The 9003 is designated as an ANSI standard bulb recognized in the United States and Canada, distinguishing it from the functionally similar H4 bulb used under European ECE standards.
Although the 9003 and H4 share the same dual-filament halogen design and P43t base, they are governed by different regulatory standards and are not certified as interchangeable in all applications.