International S1824 front turn signal bulbs use 1156 size while rear turn signal bulbs use 1157 size. The replacement chart covers 1980 to 1985 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International S1824 uses the 1156 bulb for the front turn signal across all available model years, spanning 1980-1985.
The 1156 is an ANSI-standard single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base. The single filament means it serves one lighting function only.
The BA15s base designation indicates a single-contact bayonet mount with a 15mm collar, which is not interchangeable with dual-contact bayonet bases.
The rear turn signal on the International S1824 uses the 1157 bulb across the same 1980-1985 model year range.
The 1157 is an ANSI-standard dual-filament bulb rated at 12V with a 21W/5W output, fitted with a BAY15d bayonet base. The two filaments allow it to serve two lighting functions, typically turn signaling and running light operation, within a single housing.
The BAY15d base on the 1157 features offset pins that prevent incorrect insertion, and it is physically distinct from the BA15s base used by the 1156. The two bulb types are not interchangeable despite sharing a similar bayonet-style mounting format.
Both the 1156 and 1157 are recognized under ANSI standards applicable in the United States and Canada, indicating standardized electrical and physical specifications for both bulb types.
The front and rear turn signal positions on the International S1824 require different bulb types, with the single-filament 1156 at the front and the dual-filament 1157 at the rear.