International S2554 Back Up Light Bulb Size

The International S2554 back up light requires a single 1156 bulb size for proper installation and function. Data for the specified component covers a range from 1981 to 1989.

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
1981-1989	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 International S2554 uses the 1156 bulb for the back up light across all listed model years, spanning 1981-1989.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, which is consistent with its application as a dedicated back up light.
The 1156 operates at 12 volts and 21 watts, placing it within the standard low-voltage automotive electrical range.
The 1156 uses a BA15s bayonet base, a single-contact bayonet mount where the "s" denotes a single pin, as opposed to the dual-pin BA15d variant.
The BA15s base type is not interchangeable with dual-contact bayonet bases such as the BA15d, as the pin configurations differ physically.
The 1156 conforms to ANSI standards recognized in both the United States and Canada, indicating a standardized specification shared across North American automotive applications.
Because the 1156 is a single-filament design, it cannot serve as a substitute in sockets requiring a dual-filament bulb such as the 1157, even though both share a bayonet-style base family.