The 9003 bulb is the sole bulb type specified for the UD 1400 across all listed headlight positions for the 1995-1998 model years.
The 9003 is an ANSI-standard halogen bulb recognized in both the United States and Canada, operating on a 12-volt electrical system.
The bulb carries a dual-filament design, rated at 60 watts for the high beam filament and 55 watts for the low beam filament.
Because the 9003 serves both the high beam and low beam positions on the UD 1400, a single bulb type handles both functions through its two separate filaments.
The 9003 uses a P43t base, which is a bayonet-style mount with a 43mm collar, and fitment requires a socket compatible with that specific base type.
The 9003 and H4 bulb types share the same P43t base and dual-filament configuration, though the 9003 designation reflects the ANSI standard while H4 reflects the ECE standard used outside North America; substitution between the two warrants verification of voltage and wattage compatibility.