The Mazda B2600 front and rear turn signal bulbs utilize 1156 and 1157 bulb sizes, with the front position requiring the 1156 size exclusively. The replacement chart covers 1987 through 1993 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156 bulb is an ANSI-standard single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base. It is the dominant bulb type across the Mazda B2600 turn signal specifications, appearing in both front and rear positions for the majority of model years covered.
The front turn signal on the Mazda B2600 uses the 1156 bulb without exception across all listed model years, 1987-1993.
The rear turn signal also uses the 1156 bulb for 1987-1991 and 1993, making it the standard fitment for that position across six of the seven listed model years.
The 1157 bulb is specified exclusively for the 1992 rear turn signal. It is an ANSI-standard dual-filament bulb rated at 12V with a 21W primary filament and a 5W secondary filament, fitted with a BAY15d bayonet base.
The BA15s base of the 1156 and the BAY15d base of the 1157 are physically distinct. The BA15s is a single-contact base, while the BAY15d is a dual-contact base with offset pins. These two bulbs are not interchangeable.
The offset pins on the BAY15d base of the 1157 are a keying feature that prevents incorrect installation orientation, a design absent from the single-contact BA15s base used by the 1156.
Both the 1156 and 1157 operate on a 12V electrical system, consistent with standard automotive voltage. The shared 21W rating on the primary filament means both bulbs produce equivalent light output for the turn signal function.
The 1157 specified for the 1992 rear turn signal carries a secondary 5W filament, which in automotive applications typically serves a parking or running light function in addition to the turn signal function. The 1156 used in all other positions has no such secondary filament.