Peterbilt 386 Back Up Light Bulb Size

The Peterbilt 386 back up light utilizes 1156 and P21W bulb sizes for the rear illumination system. Data for the specified components covers the period from 2006 through 2016.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2011-2016	1156
2006-2009	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Peterbilt 386 uses the 1156 bulb for the back up light across the 2006-2009 and 2011-2016 model years.
The 1156 is an ANSI-standardized bulb type, meaning its physical and electrical specifications are governed by a recognized North American standard shared across the United States and Canada.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard incandescent automotive lighting.
The 1156 is a single-filament bulb, meaning it serves only one lighting function, which in this application is the back up light.
The BA15s bayonet base on the 1156 features a single locating pin on the base collar, and this detail is critical for fitment, as the closely related 1157 bulb uses a dual-pin BA15d base and is not interchangeable despite a similar appearance.
The BA15s base designation indicates a bayonet-style mount with a 15mm base width, a common format in automotive lighting that allows the bulb to be inserted and locked with a push-and-twist motion.
Because the 1156 is an ANSI-standard type, aftermarket and OEM-equivalent replacements from various manufacturers are generally produced to the same base and voltage specifications, supporting broad parts availability for the Peterbilt 386.