Chevrolet B7 Back Up Light Bulb Size

The Chevrolet B7 back up light utilizes 1156 and P21W bulb sizes according to the provided specifications for the vehicle. Data for the specified components covers the range from 1993 through 2002.

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
1993-2002	1156

Bulb Specifications

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

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Additional Notes

The 1156 is the sole back up light bulb size specified for the Chevrolet B7 across the 1993-2002 model years.
The 1156 is an ANSI-standardized bulb type recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical parameters shared across manufacturers.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard automotive incandescent output levels for reverse lighting applications.
The bulb uses a BA15s bayonet base, a single-contact fitting where the "s" designation indicates a single pin, as opposed to the dual-pin BA15d variant. These two base types are not interchangeable despite sharing the same 15mm collar width.
The 1156 is a single-filament bulb, meaning it serves one lighting function only. This distinguishes it from dual-filament types such as the 1157, which handles two functions through separate filaments within the same housing.
Because the 1156 and 1157 share the BA15 base family but differ in pin count and filament configuration, substituting one for the other is not supported by these specifications.