Kenworth K130 front turn signal bulbs use 1157 size while rear turn signal bulbs accommodate either 1156 or 1157 size. The replacement chart covers vehicle production spanning 1987 to 1993.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Kenworth K130 front turn signal position uses the 1157 bulb across all listed model years, spanning 1987-1993.
The 1157 is a dual-filament bulb operating at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base.
The BAY15d base features two offset pins at different heights, a physical design that prevents accidental installation of a single-filament bulb in a dual-filament socket.
The rear turn signal position on the Kenworth K130 does not follow a single consistent bulb type across all listed years, with 1157 specified for 1988 and 1992, and 1156 specified for 1987, 1989-1991, and 1993.
The 1156 is a single-filament bulb operating at 12V with a 21W output, mounted on a BA15s bayonet base.
The BA15s base uses a single pin, making it physically incompatible with the dual-pin BAY15d socket used by the 1157, so the two bulb types are not interchangeable despite sharing the same wattage on their primary filaments.
Both the 1157 and 1156 are classified under ANSI standards and are recognized in both the United States and Canada.
Because the rear turn signal position alternates between the 1156 and 1157 across different model years, the correct bulb type for that position requires verification against the specific year of the vehicle before replacement.