International S1954 Back Up Light Bulb Size

The International S1954 back up light requires a bulb size of 1156 for the rear lighting assembly. Data for the specified component covers the range from 1981 through 1990.

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
1981-1990	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 S1954 uses the 1156 bulb for its back up light across the 1981-1990 model years.
The 1156 is an ANSI-standardized bulb type, meaning its physical and electrical specifications are governed by a recognized North American standard shared across the United States and Canada.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard automotive incandescent backup lighting of that era.
The 1156 uses a BA15s bayonet base, a single-contact mount where the "s" denotes a single pin, distinguishing it from double-contact bayonet variants that are not interchangeable with it.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, as opposed to dual-filament types that handle two functions such as braking and running light simultaneously.
Because the BA15s base is a single-contact design, substituting a double-contact bayonet bulb such as the 1157 would result in an incompatible fit despite the similar base appearance.