Ford E-350 brake bulbs utilize 3157, 3357, and 1157 sizes, while the center high mount stop light requires a 912 bulb size. The replacement chart covers vehicle production spanning 1975 to 1998 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 Ford E-350 brake light specifications cover model years 1975 through 1998, with three distinct bulb types used across that span: the 1157, 3357, and 3157.
The 1157 is the most historically prevalent brake bulb in these specifications, fitted to the Ford E-350 from 1975 through 1987. It is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with filaments drawing 21W and 5W respectively.
The BAY15d bayonet base of the 1157 is an offset twin-pin mount, a design that physically prevents incorrect insertion and distinguishes it from single-pin bayonet types.
The 3357 replaced the 1157 for brake light duty on the Ford E-350 for model years 1992-1995. Unlike the 1157, the 3357 is a single-filament wedge bulb in a T25 form factor, rated at 12V and 27W.
The 3157 is specified for the Ford E-350 brake lights from 1996-1998. It shares the T25 wedge form factor with the 3357 but is a dual-filament type, rated at 12V with filaments drawing 27W and 7W.
Although the 3157 and 3357 share the same T25 wedge base and housing size, their filament configurations differ. The 3357 carries a single filament while the 3157 carries two, and substituting one for the other without confirming socket compatibility may result in incorrect brake light function.
The 912 bulb is specified exclusively for the Center High Mount Stop Light on the Ford E-350 for model years 1992-1998. It is a T15 wedge bulb rated at 12V and 12W, and is noted as a variant of the 921 bulb type.
The 912 and 921 share the same T15 wedge base, but they differ in wattage. The 912 is rated at 12W while the 921 is typically rated at 18W, making them physically interchangeable in the socket but electrically distinct.
All four bulb types in these specifications, the 1157, 3157, 3357, and 912, conform to ANSI standards recognized in both the United States and Canada, indicating standardized electrical and physical tolerances across manufacturers.
The transition from the bayonet-base 1157 to the wedge-base 3357 and 3157 across the E-350 model year range reflects a base-type change that makes those bulb generations physically non-interchangeable despite overlapping voltage ratings.