Ford Fiesta Back Up Light Bulb Size

Ford Fiesta back up light bulbs utilize 921 and 1156 bulb sizes across various model generations. The replacement chart covers vehicle production spanning from 1978 to 2019.

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
2014-2019	921
1978-1980	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Ford Fiesta back up light specifications cover two distinct bulb types across the listed model years: the 921 and the 1156.
The 921 is the back up light bulb size for the Ford Fiesta across the 2014-2019 model years.
The 921 bulb follows the ANSI standard applicable in the US and Canada, uses a T15 wedge base, and operates at 12V with a 16W output.
A wedge base bulb, such as the 921, is held in its socket by the tension of the base itself rather than by a locking mechanism, which distinguishes it from bayonet-style bulbs.
The 1156 is the back up light bulb size for the 1978-1980 model years.
The 1156 bulb also follows the ANSI standard for the US and Canada, uses a BA15s single-contact bayonet base, and operates at 12V with a 21W output.
A BA15s bayonet base features a single contact pin and requires a push-and-twist motion to seat into its socket, a fitment style that is physically incompatible with the wedge socket used by the 921.
The 921 and 1156 are not interchangeable, as their base types, socket designs, and wattage ratings all differ from one another.
Although both bulb types share a 12V operating voltage, the 1156 draws 21W compared to the 921's 16W, meaning the two are not electrically equivalent for direct substitution.