GMC V2500 Suburban Back Up Light Bulb Size

The GMC V2500 Suburban back up light uses a 1156 bulb size for this model. The replacement chart covers 1987 through 1991 production years with corresponding bulb size specifications.

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
1987-1991	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 GMC V2500 Suburban uses the 1156 bulb for the back up light across all listed model years, spanning 1987-1991.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, which in this application is the reverse light circuit.
It operates on a 12-volt electrical system and draws 21 watts, consistent with standard automotive incandescent output for reverse lighting.
The 1156 uses a BA15s bayonet base, where "BA15s" denotes a single-contact bayonet fitting with a 15mm base width.
The single-contact design of the BA15s base distinguishes it from the BA15d double-contact base used on dual-filament bulbs, and the two are not interchangeable.
The 1156 carries ANSI standardization recognized in both the United States and Canada, placing it within a regulated specification for electrical and physical characteristics.