Isuzu FXR Back Up Light Bulb Size

The Isuzu FXR back up light utilizes a 1156 bulb size for the specific lighting component. Data for the bulb application covers the range from 2004 to 2011.

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
2004-2011	1156 (Tilt Cab)

Bulb Specifications

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

Other Locations

Additional Notes

The 1156 is the sole back up light bulb size listed for the Isuzu FXR across the 2004-2011 model years, applying specifically to the Tilt Cab configuration.
The 1156 is an ANSI-standard bulb recognized in both the United States and Canada, meaning it conforms to a widely adopted North American specification for automotive lighting.
This bulb operates on a 12-volt electrical system and draws 21 watts, which is typical for incandescent reverse lighting applications in commercial vehicles.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, distinguishing it from the dual-contact BA15d variant used in other applications.
As a single-filament bulb, the 1156 is designed to perform one lighting function only, which aligns with its dedicated use as a back up light rather than a combined stop/tail unit.
The BA15s base type is not interchangeable with dual-filament bulbs such as the 1157, which shares a similar physical form but carries a BA15d base with two offset pins. Substituting one for the other is not compatible without modification.
The Tilt Cab designation in the specifications indicates that the listed fitment applies to that specific cab style of the FXR, and not necessarily to other cab configurations that may exist within the broader FXR lineup.