The International S1754 uses a 1156 bulb size for the front turn signal and a 1157 bulb size for the rear turn signal. The replacement chart covers vehicle production spanning 1981 to 1989.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International S1754 uses the 1156 bulb for the front turn signal across all documented model years from 1981-1989.
The 1156 is a single-filament bulb operating at 12 volts and 21 watts, fitted with a BA15s bayonet base, and is recognized under ANSI standards in both the United States and Canada.
The BA15s bayonet base features a single contact pin, which physically prevents substitution with dual-filament bayonet bulbs that use offset pins.
The rear turn signal on the International S1754 uses the 1157 bulb across all documented model years from 1981-1989.
The 1157 is a dual-filament bulb rated at 12 volts with two wattage outputs, 21 watts on the primary filament and 5 watts on the secondary, also recognized under ANSI standards in the United States and Canada.
The 1157 uses a BAY15d bayonet base, which has two offset contact pins corresponding to its two filaments, making it electrically and physically distinct from the 1156.
Because the 1156 and 1157 share the same 12-volt operating voltage but differ in base type and filament count, the two bulbs are not interchangeable despite their similar appearance.
The dual-filament design of the 1157 allows the rear turn signal housing to serve two lighting functions through a single bulb, typically combining turn signal and running or brake light duties.