The GMC V1500 Suburban front turn signal requires a 3057NA or 2057NA bulb size, while the rear turn signal uses a 2057 bulb size. The replacement chart covers 1987 through 1991 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 GMC V1500 Suburban uses three distinct bulb types across its front and rear turn signal positions: the 3057NA, 2057NA, and 2057.
The 3057NA and 2057NA bulbs feature natural amber glass, which produces an amber-colored output without the need for an amber lens or housing filter.
The 2057 used in the rear turn signal position across all five model years (1987-1991) has a clear glass envelope, meaning the amber color in that application is produced by the lens rather than the bulb itself.
The front turn signal on the GMC V1500 Suburban transitioned from the 2057NA (1987-1988) to the 3057NA (1989-1991), representing a change in both base type and bulb construction.
The 3057NA uses a T25 wedge base, while the 2057NA uses a BAY15d bayonet base. These two base types are physically incompatible with each other, so the 3057NA and 2057NA are not interchangeable despite both being dual-filament natural amber bulbs.
Both the 2057NA and 2057 share the same BAY15d bayonet base and identical wattage ratings of 26.9W on the high filament and 8W on the low filament, differing only in glass color.
All three bulb types are dual-filament designs, operating at 12 volts. Dual-filament bulbs serve two functions within a single housing, typically combining turn signal and parking light duties.
The 2057NA and 2057 are described as brighter variants of the 1157, sharing the same BAY15d base. However, the 1157 is not listed as a specified fitment for any position on the V1500 Suburban and is not a direct substitute without confirming socket and wattage compatibility.