International 9400 License Plate Bulb Size

The International 9400 license plate light requires a single 1157 bulb size for the specific lighting component located at the rear of the vehicle. Available data covers the period from 1990 through 1997 for the specified truck series.

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
1990-1997	1157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157

Other Locations

Additional Notes

The 1157 is the sole bulb type specified for the license plate position across the International 9400 for model years 1990-1997.
The 1157 is an ANSI-standardized bulb recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical parameters shared across those markets.
The 1157 is a dual-filament bulb, which means it contains two separate tungsten filaments within a single glass envelope, each operating at a different wattage.
The two filaments in the 1157 operate at 21W and 5W respectively on a 12-volt circuit, with the higher-wattage filament typically serving a brighter function and the lower-wattage filament serving a reduced-intensity function.
The 1157 uses a BAY15d bayonet base, a two-pin offset base design in which the two pins are positioned at different heights along the base to prevent incorrect insertion orientation.
The offset pin arrangement of the BAY15d base is a deliberate fitment control feature, as it physically prevents a dual-filament bulb from being seated in a position that would connect the filaments to the wrong circuits.
A single-filament bulb sharing the same bayonet base family, such as the 1156, is not a direct substitute for the 1157 in this application, as the pin offset and filament configuration differ between the two types.