The Peterbilt 386 front turn signal requires a 3157NA or 2057 bulb size, while the rear turn signal uses a 1157 or 2057 bulb size. The replacement chart covers vehicle production years spanning 2006 to 2016 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 Peterbilt 386 front turn signal uses the 3157NA bulb for model years 2011-2016 and the 2057 bulb for model years 2006-2009.
The rear turn signal on the Peterbilt 386 follows the same year-based split, with the 1157 fitted in 2011-2016 models and the 2057 in 2006-2009 models.
The 3157NA is a dual-filament T25 wedge bulb rated at 12V with a high filament draw of 27W and a low filament draw of 7W, conforming to ANSI standards for the US and Canada.
The natural amber glass of the 3157NA produces a color-filtered output directly from the bulb itself, rather than relying on a colored lens housing to achieve the amber signal appearance.
The 2057 and 1157 bulbs both use a BAY15d bayonet base, which is a two-pin offset base design that physically locks the bulb into the socket and ensures correct filament orientation.
Although the 2057 and 1157 share the same BAY15d base, they are not equivalent in output. The 2057 operates at 26.9W/8W while the 1157 operates at 21W/5W, making the 2057 the higher-output variant of the two.
The shared base type between the 2057 and 1157 means physical fitment is possible in either socket, but substituting one for the other would result in a difference in filament wattage that may not match the original circuit design.
All three bulb types listed are dual-filament designs, meaning each bulb contains a separate high-intensity filament and a lower-intensity filament, typically serving distinct functions such as turn signaling and running light operation within a single housing.
All bulbs across both sub-parts are rated at 12V and comply with ANSI standards applicable to both the United States and Canada.
The 3157NA uses a wedge base rather than a bayonet base, making it mechanically incompatible with the sockets used by the 2057 and 1157, despite all three being dual-filament 12V bulbs.