The Lexus SC300 front turn signal requires a 1157NA or 1034NA bulb size, while the rear turn signal uses a 7440 or 1156 bulb size. The replacement chart covers 1992 through 2000 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 Lexus SC300 front turn signal uses two distinct bulb types across its production years: the 1157NA and the 1034NA, both of which are dual-filament bulbs with a BAY15d bayonet base rated at 12V and 21W/5W.
The 1034NA is an ANSI-standard variant of the 1157NA, sharing the same BAY15d bayonet base, natural amber glass, and 12V/21W/5W electrical ratings.
The front turn signal on the Lexus SC300 used the 1157NA for the 1992-1995 model years, with the exception of 1992, which used the 1034NA.
The 1034NA bulb was specified for the SC300 front turn signal in 1996-1999, while the 1157NA returned for the 2000 model year.
Because the 1034NA and 1157NA share the same BAY15d base and wattage ratings, their close relationship as ANSI variants may be relevant when sourcing replacements, though they are listed as separate part numbers across different model years.
The rear turn signal on the Lexus SC300 transitioned from the 1156 to the 7440 between the 1996 and 1997 model years, representing a change from a BA15s bayonet base to a T20 wedge base.
The 1156 is a single-filament bulb with a BA15s bayonet base rated at 12V and 21W, and it was specified for the SC300 rear turn signal across the 1992-1996 model years.
The 7440 is a single-filament T20 wedge bulb rated at 12V and 21W, and it was specified for the SC300 rear turn signal across the 1997-2000 model years.
The 1156 and 7440 use physically incompatible bases, a BA15s bayonet and a T20 wedge respectively, making them non-interchangeable despite sharing the same wattage rating.
All four bulb types listed across the SC300 turn signal specifications conform to ANSI standards applicable in both the United States and Canada.