Peterbilt 384 Back Up Light Bulb Size

The Peterbilt 384 back up light utilizes 1156 and P21W bulb sizes for the rear illumination components. Data for the specific lighting requirements covers the period from 2008 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
2008-2009	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 384 uses the 1156 bulb for its back up light across all listed model years from 2008-2016.
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 and draws 21 watts, which is consistent with standard automotive incandescent backup light applications.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, as opposed to dual-filament types that handle two functions such as braking and running lights simultaneously.
The 1156 uses a BA15s bayonet base, where "BA15s" denotes a single-contact bayonet fitting with a 15mm base width, a common automotive socket type.
The BA15s base is not interchangeable with the BA15d base, which is a dual-contact variant of the same bayonet family used in different bulb types.
The 1156 is sometimes cross-referenced with the 7506 bulb in international markets, though fitment confirmation against the original specification is advisable before substitution.