Ford F-250 Back Up Light Bulb Size

The Ford F-250 back up light utilizes bulb sizes 1156, 199, 2356, 2456, 3156, and P21W depending on the specific version of the component. Provided data covers the range from 1969 to 1999 for the specified vehicle and lighting equipment.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1994-1999	3156
1992-1993	1156
1989-1991	3156
1971-1988	1156
1969-1970	199

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament wedge bulb (T25). 12V, 27W.	3156
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W.	199

Other Locations

Additional Notes

The Ford F-250 backup light specifications cover model years 1969 through 1999, with three distinct bulb sizes used across that span: 3156, 1156, and 199.
The 3156 is a single-filament wedge bulb in the T25 form factor, rated at 12V and 27W, and conforms to the ANSI standard recognized in the US and Canada.
The 1156 is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base, and also carries ANSI recognition for the US and Canadian markets.
The 199 shares the BA15s bayonet base and the 12V, 21W rating of the 1156, and is classified as a variant of that bulb type under the same ANSI standard.
The Ford F-250 uses the 3156 for model years 1994-1999, as well as for 1989-1991, making it the bulb associated with the later portion of the covered range.
The 1156 is specified for model years 1971-1988, as well as for 1992 and 1993, representing the most frequently recurring bulb across the full span of these specifications.
The 199 bulb is specific to the 1969 and 1970 Ford F-250, the two earliest model years in these specifications.
Although the 199 and 1156 share the same base type, voltage, and wattage, they carry distinct ANSI designations and are not listed interchangeably within these specifications.
The 3156 wedge base and the 1156 bayonet base are physically incompatible socket types, meaning the two bulbs are not interchangeable regardless of any similarity in electrical output.
The specifications reflect two separate base technologies across the Ford F-250 backup light history: the BA15s bayonet base associated with the 1156 and 199, and the wedge base associated with the 3156.