Ford B-600 front and rear turn signal bulbs utilize 1157 and 1156 bulb sizes respectively. The replacement chart covers vehicle production spanning 1980 to 1994.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1157 bulb is the dominant specification across the Ford B-600 turn signal positions, appearing in both the front and rear turn signal roles across the 1980-1994 model range with only one exception in the rear position.
The 1157 is a dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base. The dual-filament design allows a single bulb to serve both signaling and running light functions within the same housing.
The 1156 is a single-filament bulb rated at 12V and 21W, using a BA15s bayonet base. Although its wattage matches the primary filament of the 1157, the base type and filament count differ, making the two bulbs physically and functionally distinct.
The Ford B-600 rear turn signal for the 1992 model year specifies the 1156 rather than the 1157 used in all other listed years. This represents a direct compatibility difference that affects base type and filament configuration.
Because the BAY15d base of the 1157 and the BA15s base of the 1156 are not the same, the two bulbs are not interchangeable despite sharing a similar physical profile and identical primary wattage. Installing the wrong type risks improper seating or circuit behavior.
Both the 1157 and 1156 are ANSI-standardized bulbs recognized in the United States and Canada, meaning replacement units from multiple manufacturers are widely produced to the same electrical and base specifications.
The front turn signal position on the Ford B-600 uses the 1157 without variation across the entire 1980-1994 span covered by the specifications, indicating a consistent socket and circuit design for that position throughout those years.