The Mazda B1800 front and rear turn signal bulbs both utilize a 1157 bulb size for proper operation. The replacement chart covers 1977 to 1978 model 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 Mazda B1800 uses the 1157 bulb across both its front and rear turn signal positions for the 1977-1978 model years.
The 1157 is a dual-filament bulb, meaning it contains two separate filaments within a single envelope, allowing it to serve two distinct lighting functions at different wattages.
It operates on a 12-volt electrical system and draws 21 watts on its primary filament and 5 watts on its secondary filament, reflecting its dual-purpose design.
The 1157 uses a BAY15d bayonet base, which features two offset pins at different heights to ensure the bulb is seated in the correct rotational position during installation.
The 1157 designation follows ANSI standards, meaning the bulb conforms to a standardized specification recognized across the United States and Canada.
Because the same bulb number applies to both the front and rear turn signal positions across both model years covered, the B1800 requires no position-specific or year-specific bulb variants for its turn signal circuit.