Peterbilt 330 Turn Signal Bulb Size

Additional Notes

• The Peterbilt 330 front turn signal uses two distinct bulb types across its model years: the 3157NA for 2011-2017 and the 2057 for 1996-2009, with 1995 and 1997 carrying additional fitment-specific variants.
• The 3157NA is a dual-filament wedge bulb rated at 12V with a 27W high filament and 7W low filament. Its natural amber glass produces a yellow-tinted output without relying on a colored lens or coating.
• The 2057 uses a BAY15d bayonet base and operates at 12V with filaments rated at 26.9W and 8W. It is a higher-output variant of the 1157, sharing the same base type but drawing more current on its primary filament.
• The 1157, which appears in the Peterbilt 330 rear turn signal position for 2011-2017, shares the BAY15d bayonet base with the 2057 but operates at lower wattages of 21W and 5W. Despite the shared base, the two bulbs are not rated identically and serve different positions in this application.
• The rear turn signal on the Peterbilt 330 shifted from the 2057 to the 1157 between the 2009 and 2011 model years, meaning the front and rear positions no longer shared a common bulb type during the 2011-2017 period.
• For the 1997 model year, the front turn signal specification lists two separate bulbs: the 2057 as the standard fitment and the 198 for vehicles equipped with 4 round headlamps, indicating a configuration-dependent difference in that year.
• The 1995 model year similarly carries two front turn signal entries: the 198 as a base fitment and the 2057 for vehicles with halogen capsule headlamps, reflecting a headlamp-type dependency on bulb selection.
• The 198 is a miniature wedge bulb rated at only 12V and 2W, placing it in a significantly lower power class than the 2057 or 3157NA. Its use in specific 1995 and 1997 configurations suggests it served a limited or auxiliary signaling role tied to particular headlamp assemblies.
• The 3157NA and 2057 are both ANSI-standardized dual-filament bulbs, but they use different base types. The 3157NA uses a wedge base while the 2057 uses a BAY15d bayonet base, making them physically non-interchangeable despite overlapping voltage ratings.
• All four bulb types listed across these specifications, the 3157NA, 2057, 198, and 1157, conform to ANSI standards applicable in both the United States and Canada.