Dodge Sprinter front and rear side marker bulbs utilize 3457NA and 3357NA sizes for forward positions, with 12821 and 12961 sizes for rearward locations. The replacement chart covers 2003 through 2009 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 Dodge Sprinter front side marker uses two distinct bulb types across its model years: the 3357NA for 2003-2004 and the 3457NA for 2005-2006.
Both the 3357NA and 3457NA are ANSI-standardized T25 wedge bulbs rated at 12V with natural amber glass, making them compliant with US and Canadian regulations without requiring a colored lens to produce an amber output.
The 3457NA is a dual-filament bulb rated at 27W and 7W, while the 3357NA carries a single filament rated at 27W. These two bulbs share the same T25 form factor but differ in filament count, which makes them non-interchangeable despite their physical similarity.
The rear side marker of the Dodge Sprinter uses two different Philips-numbered bulbs depending on the model year: the 12821 for 2003-2004 and 2007-2009, and the 12961 for 2005-2006.
Both the 12821 and 12961 are T10 miniature wedge bulbs sharing the same W2.1x9.5d base, 12V rating, and 5W output. The W2.1x9.5d designation refers to a standardized wedge base where the number reflects the contact width and pin spacing in millimeters.
Because the 12821 and 12961 share identical base type, voltage, and wattage ratings, their fitment difference across model years is likely tied to minor optical or construction variations specific to each Philips part number rather than electrical incompatibility.
The front side marker position on the Dodge Sprinter uses significantly higher-wattage bulbs (27W) compared to the rear side marker position (5W), reflecting a functional distinction between the two positions in terms of visibility requirements.
The 3457NA and 3357NA bulbs used in the front side marker position are governed by ANSI standards, whereas the 12821 and 12961 bulbs used in the rear are identified by Philips part numbers, indicating different classification systems apply to each position.