The Mazda B2500 front turn signal requires a 3157NA or 3157 bulb size, while the rear turn signal uses a 2356 or 2456 bulb size. The replacement chart covers 1998 to 2001 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 3157 and 3157NA are the most frequently specified bulbs across the Mazda B2500 front turn signal positions, appearing across all four model years from 1998-2001.
Both the 3157 and 3157NA are dual-filament T25 wedge bulbs rated at 12V with a 27W high-filament and 7W low-filament output, conforming to ANSI standards applicable in the US and Canada.
The 3157NA differs from the standard 3157 in that its glass envelope is tinted natural amber, which produces an amber signal output without relying on a colored lens.
The Mazda B2500 front turn signal shifted from the 3157 to the 3157NA between the 1998-1999 and 2000-2001 model years, indicating a change in lens or housing design that required the natural amber variant.
Because the 3157 and 3157NA share the same T25 wedge base and electrical ratings, physical fitment is interchangeable, but substituting a clear 3157 in a position specified for the 3157NA may affect the color output of the turn signal if the housing lacks an amber lens.
The rear turn signal on the Mazda B2500 uses the 2456 for the 1998-2000 model years, which is a festoon-style bulb rated at 12V and designated for specialty applications under ANSI standards.
The 2001 Mazda B2500 rear turn signal specifies the 2356, a dual-filament bulb with a BAY15d bayonet base rated at 12V, representing a distinct base type that is not interchangeable with the festoon-style 2456 used in prior years.
The BAY15d bayonet base of the 2356 is an offset twin-contact base, a configuration commonly used in automotive stop and tail light applications to prevent incorrect single-filament substitution.
The festoon format of the 2456 refers to a cylindrical bulb with end-cap contacts, a form factor physically incompatible with bayonet-style sockets, reinforcing that rear turn signal components are not shared between the 2001 and earlier model years.
All bulb types specified across both the front and rear turn signal positions on the B2500 conform to ANSI standards for the US and Canadian markets.