GMC V3500 front turn signal bulbs use 2357NA or 2057NA sizes, while rear turn signal bulbs use 3057 or 2057 sizes. The replacement chart covers 1987 to 1991 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 GMC V3500 front turn signal uses the 2357NA bulb for model years 1988-1991, while the 1987 model year uses the 2057NA instead.
The 2357NA and 2057NA are both ANSI-standard dual-filament bulbs rated at 12V with a 26.9W high-filament and 8W low-filament output, sharing the BAY15d bayonet base.
Both the 2357NA and 2057NA feature natural amber glass, which produces the amber turn signal color without requiring a colored lens or separate amber coating.
The BAY15d bayonet base found on the 2357NA, 2057NA, and 2057 is an offset-pin base, meaning the two pins are positioned at different heights to ensure correct polarity orientation during installation.
The 2057NA is described as a brighter variant of the 1157, indicating it produces higher light output than the 1157 while retaining the same base type and general form factor.
The GMC V3500 rear turn signal transitions from the 2057 bulb in 1987-1989 to the 3057 in 1990-1991, representing a change in bulb type between those model year groups.
The 3057 is a dual-filament wedge bulb in the T25 form factor, rated at 12V with 27W and 7W filaments, and it does not use a bayonet base, making it physically incompatible with sockets designed for BAY15d bulbs.
The 2057 rear turn signal bulb shares its BAY15d bayonet base and 12V, 26.9W/8W rating with the 2057NA front bulb, though the 2057 lacks the natural amber glass of its NA-designated counterpart.
Because the 3057 uses a wedge base and the 2057 uses a BAY15d bayonet base, the rear turn signal sockets on 1987-1989 V3500 models are not interchangeable with those on 1990-1991 models.
All bulb types listed across both front and rear positions conform to ANSI standards recognized in both the United States and Canada.