Ford Gran Torino Back Up Light Bulb Size

The Ford Gran Torino back up light uses bulb size 1156 or P21W depending on the specific version of the vehicle. Data for the lighting components covers the range from 1972 to 1976.

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
1972-1976	1156

Bulb Specifications

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

Other Locations

Additional Notes

The Ford Gran Torino uses the 1156 bulb across all listed model years, spanning 1972-1976, for the back up light position.
The 1156 is an ANSI-standardized bulb recognized across the United States and Canada, meaning it conforms to a defined set of electrical and physical standards shared by multiple manufacturers.
This bulb operates on a 12-volt system at 21 watts, which is consistent with standard automotive electrical systems of that era.
The 1156 is a single-filament bulb, meaning it serves only one lighting function rather than switching between two brightness levels as a dual-filament bulb would.
It uses a BA15s bayonet base, where "BA15s" denotes a single-contact bayonet fitting with a 15mm base width. The single-contact design corresponds directly to the single-filament construction.
The BA15s base type is a locking-style mount that secures the bulb with a twist rather than a threaded connection, a common fitment method in automotive applications of this period.
Because the 1156 carries an ANSI designation, aftermarket and OEM replacements from different suppliers are generally interchangeable as long as they carry the same 1156 rating.
The consistent use of the same bulb specification across the entire 1972-1976 production run of the Gran Torino indicates no back up light bulb changes occurred within that span according to the provided data.