Ford F-250 Brake Bulb Size

Additional Notes

• The Ford F-250 brake light specifications cover model years 1953 through 1999, with four distinct bulb types used across that span: the 1154, 1034, 198, 1157, and 3157.
• The 3157 is the most widely specified brake bulb across this data set, covering the Ford F-250 from 1988-1999. It is a dual-filament T25 wedge bulb rated at 12V with a 27W high-filament and 7W low-filament output, conforming to ANSI standards for the US and Canada.
• The 1157 is the second most frequently specified bulb, used on the F-250 from 1973-1987. It is a dual-filament bulb with a BAY15d bayonet base, rated at 12V, 21W/5W, and also meets ANSI standards for the US and Canada.
• Although the 3157 and 1157 share a dual-filament design and serve the same brake light function, they are not interchangeable. The 3157 uses a wedge base while the 1157 uses a BAY15d bayonet base, meaning the socket type differs between the two generations of F-250.
• The bulb 198, specified for the F-250 from 1963-1972, is a miniature T5 wedge bulb rated at only 12V, 2W. This output is substantially lower than the dual-filament bulbs used in later model years, reflecting an older brake light design standard.
• The 1034, used on the F-250 from 1956-1962, shares the BAY15d bayonet base with the 1157 and carries the same 12V, 21W/5W rating. It is classified as a variant of the 1157, though the two are not confirmed as direct drop-in replacements without verifying socket compatibility.
• The 1154, specified for the F-250 from 1953-1955, also uses a BAY15d bayonet base and is described as an older variant of the 1157. Unlike the 1157 and 1034, the 1154 is rated for both 6V and 12V operation, indicating it was designed for an era when 6-volt electrical systems were still in use.
• The Center High Mount Stop Light (CHMSL) specifications apply to the F-250 for model years 1994-1999 and use T15 wedge bulbs across all listed years, specifically the 921, 922, and 912 types, all rated at 12V.
• The 921 and 922 are both T15 wedge bulbs rated at 12V, 16W, and the specifications treat them as separate part numbers. The 912 is a variant of the 921 but is rated at a lower 12W output, making it a distinct specification despite sharing the same T15 wedge form.
• The CHMSL bulb specification for the F-250 is not uniform across its listed years. The 1995-1996 model years differ from each other, with 1995 using the 921 and 1996 using the 922, and 1998-1999 also differ, with 1998 using the 912 and 1999 using the 922, indicating that substitution between these T15 variants should be verified against the specific model year.