The UD 1800 uses a 9003 bulb size for both high beam and low beam headlight applications. Replacement specifications in the chart span 1995 to 1998 model years.
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 for the UD 1800 across all listed headlight positions for the 1995-1998 model years.
The 9003 is a dual-filament halogen bulb, meaning a single unit contains separate filaments for both high and low beam operation.
Because the 9003 serves both the high beam and low beam positions on the UD 1800, one bulb type covers both headlight functions.
The 9003 operates on a 12-volt electrical system and draws 60 watts on the high beam filament and 55 watts on the low beam filament.
The 9003 uses a P43t base, which is a standardized bayonet-style fitting that determines physical compatibility with a given headlight housing.
The 9003 carries ANSI standardization recognized in both the United States and Canada, meaning it conforms to a defined set of performance and construction criteria in those markets.
The 9003 and H4 bulb share the same dual-filament halogen design and P43t base, though they originate from different standardization systems; substitution between them requires verification of housing fitment before use.