The Lincoln LS front turn signal requires a 3457NA or 3157 bulb size, while the rear turn signal uses a 3157NA, 2456, or 3156 bulb size. The replacement chart covers vehicle production years spanning 2000 to 2006 with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lincoln LS front turn signal uses the 3457NA bulb for model years 2003-2006 and the 3157 bulb for model years 2000-2002, representing a change in specification at the 2003 model year.
The 3457NA and 3157NA are T25 wedge-base bulbs operating at 12V with a dual-filament configuration rated at 27W and 7W, where the higher wattage filament serves the turn signal function and the lower wattage filament serves a secondary lighting function.
The "NA" suffix in bulb designations such as 3457NA and 3157NA indicates natural amber glass, meaning the amber color is produced by the glass envelope itself rather than by a clear bulb installed in a colored lens housing.
The 3157 and 3457NA share identical voltage and wattage ratings (12V, 27W/7W) and both use the T25 wedge base, though the 3457NA adds natural amber glass coloring absent from the 3157.
The rear turn signal of the Lincoln LS uses four distinct bulb types across its production run: 3157NA for 2003-2006, 2456 for 2000 and 2002, and 3156 exclusively for 2001.
The 3156 bulb used in the 2001 rear turn signal position is a single-filament T25 wedge bulb rated at 12V and 27W, distinguishing it from the dual-filament bulbs used in other model years for the same position.
The 2456 is a festoon-style bulb rather than a wedge-base type, making it physically incompatible with sockets designed for T25 wedge bulbs such as the 3157NA or 3156.
All bulbs listed across both turn signal positions conform to ANSI standards applicable in the United States and Canada, indicating standardized electrical and dimensional specifications within that regulatory framework.
Because the rear turn signal position uses different bulb types across model years, including different base styles (wedge versus festoon), direct substitution between model years is not supported by the specifications.
The front turn signal position uses only T25 dual-filament wedge bulbs across all listed model years, whereas the rear turn signal position includes variation in both filament count and base type depending on the year.