The Mazda B1600 uses an H5001 bulb size for high beam headlights and an H5006 bulb size for low beam headlights. The replacement chart covers 1975 to 1976 vehicle production 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 Mazda B1600 uses the H5001 sealed beam unit for high beam headlights across the 1975-1976 model years, and the H5006 sealed beam unit for low beam headlights across the same span.
The H5001 is a 4-inch square sealed beam unit operating at 12V. It conforms to ANSI standards applicable in the United States and Canada.
The H5006 is a 5.75-inch round sealed beam unit also rated at 12V and governed by the same ANSI standards covering the US and Canadian markets.
Both the H5001 and H5006 are sealed beam units, meaning the lens, reflector, and filament are fused into a single assembly. When the filament fails, the entire unit requires replacement rather than an internal bulb swap.
The square profile of the H5001 and the round profile of the H5006 make the two units physically incompatible with each other, and neither can serve as a substitute for the other in the B1600's headlight housings.
The consistent use of H5001 and H5006 across both the 1975 and 1976 model years indicates no change in headlight specification within that production period for the Mazda B1600.