Peterbilt 337 Back Up Light Bulb Size

The Peterbilt 337 back up light requires a 1156 bulb size for proper installation and function within the rear lighting assembly. Available data covers the period from 2010 through 2017 for the specified vehicle and component.

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
2010-2017	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 337 uses the 1156 bulb for its back up lights across the 2010-2017 model years.
The 1156 is an ANSI-standardized bulb type, meaning its specifications are governed by a recognized North American standard applicable in both the United States and Canada.
The 1156 operates on a 12-volt electrical system, which is consistent with standard automotive and commercial truck electrical architecture.
The bulb draws 21 watts, placing it in the range typical of incandescent signal and utility lighting rather than high-output illumination.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, which in this application is the reverse or back up light circuit.
The base type is a BA15s bayonet mount, where "BA15" refers to the 15mm base width and "s" denotes a single contact pin, distinguishing it from dual-contact variants such as the BA15d.
The BA15s base is not interchangeable with the BA15d base found on dual-filament bulbs like the 1157, as the pin configuration and electrical contact design differ between the two.