The GMC K1500 Suburban brake light utilizes 1157, 2057, and 3057 bulb sizes depending on the specific production period for the vehicle. Available data covers the range from 1979 through 1999 for the listed components.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The GMC K1500 Suburban brake bulb specifications cover model years 1979 through 1999, along with center high mount stop light data for 1993 through 1997.
Three distinct bulb types appear across the brake light positions: the 3057, 2057, and 1157, all of which are dual-filament designs rated at 12 volts and conforming to ANSI standards recognized in both the United States and Canada.
The 3057 is a dual-filament wedge bulb in the T25 form factor, rated at 27W on the high-intensity filament and 7W on the low-intensity filament. It is specified for the GMC K1500 Suburban brake lights across the 1992-1999 model years.
The 2057 and 1157 both use the BAY15d bayonet base rather than a wedge mount, making them physically interchangeable in terms of socket type, though their wattage ratings differ.
The 1157 carries ratings of 21W and 5W across its two filaments, while the 2057 operates at 26.9W and 8W, making the 2057 the higher-output variant of the two bayonet-base bulbs.
The 2057 is specified for the 1983-1986 model years, and the 1157 is specified for the 1979-1982 model years, meaning the two bayonet-base types are not interchangeable without accounting for the wattage difference between them.
The 3057 uses a wedge base rather than a bayonet base, which means it is not a drop-in substitute for either the 2057 or the 1157 despite serving the same brake light function in later model years.
The center high mount stop light, a separate brake-related position, uses the 921 bulb for the 1993-1997 model years. The 921 is a single-filament T15 wedge bulb rated at 16W, distinct in both form factor and filament count from the bulbs used in the main brake light positions.
Because the 921 is a single-filament bulb, it does not share the dual-filament characteristic of the 3057, 2057, or 1157, and the four bulb types across these specifications are not interchangeable with one another.
All four bulb types in these specifications conform to ANSI standards, indicating standardized electrical and physical ratings applicable across manufacturers within the US and Canadian markets.