The Pontiac T1000 front turn signal requires a 2057, 1157NA, or 1157 bulb size, while the rear turn signal uses a 2057 or 1157 bulb size. The replacement chart covers 1981 through 1987 production 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 Pontiac T1000 uses three bulb types across its front and rear turn signal positions: the 2057, the 1157NA, and the 1157.
All three bulb types share the BAY15d bayonet base and dual-filament construction, making them physically similar in mounting but electrically distinct.
The 2057 operates at 26.9W on its high-filament and 8W on its low-filament, while both the 1157 and 1157NA operate at 21W and 5W respectively, reflecting a notable wattage difference between the two groups.
All three bulb types are rated at 12V and conform to ANSI standards recognized in both the United States and Canada.
The 2057 is specified for both the front and rear turn signals on the Pontiac T1000 across the 1983-1987 model years.
The 1157NA, which features natural amber glass rather than a clear envelope, was specified exclusively for the front turn signal position in the 1982 model year.
The amber tint of the 1157NA produces a colored output from the bulb itself, whereas the 2057 and standard 1157 rely on clear glass, with any amber coloring typically provided by the lens housing.
The 1157 was used in the rear turn signal position for both 1981 and 1982, while the front turn signal in 1981 also used the 1157, making it the sole bulb type across both positions in that year.
Although the 2057 and 1157 share the same BAY15d base, substituting one for the other would result in a wattage mismatch, as the 2057 draws significantly more current on its high-filament circuit.
The 1157NA and the standard 1157 share identical voltage and wattage ratings, with the only distinction being the natural amber glass coating on the 1157NA.