The Ducati 800 uses a 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers 2003 to 2004 model 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 9003 bulb is a dual-filament halogen type that operates on a single bulb housing to serve two distinct functions, with one filament dedicated to high beam output and the other to low beam output.
For the Ducati 800, the 9003 bulb serves both the high beam and low beam headlight positions across the 2003-2004 model years, meaning a single bulb type fulfills both lighting roles.
The 9003 specification is electrically and physically equivalent to the H4 bulb standard used widely in international markets, making the two designations interchangeable in practice despite carrying different names.
A 9003/H4 bulb typically operates at 60 watts on the high beam filament and 55 watts on the low beam filament, running on a 12-volt electrical system.
Because the same bulb type is specified for both the high and low beam positions, the Ducati 800 uses a single-bulb headlight design rather than a separate-bulb configuration where each function requires its own dedicated unit.
The 9003 bulb uses a three-pronged P43t base, which is a keyed fitting that allows insertion in only one orientation, preventing incorrect installation of the high and low beam filaments relative to the reflector.