Chevrolet Corvair Back Up Light Bulb Size

The Chevrolet Corvair back up light utilizes 1156 and P21W bulb sizes for the rear illumination system. Data for the specified components covers the range from 1960 to 1969.

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
1960-1969	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 Chevrolet Corvair uses the 1156 bulb for its back up light across all listed model years, spanning 1960-1969.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, which in this application is the back up light.
The 1156 operates on a 12-volt electrical system and draws 21 watts, consistent with standard automotive reverse lighting of that era.
The 1156 uses a BA15s bayonet base, a single-contact bayonet mount that locks into the socket with a twist and is not interchangeable with double-contact bayonet bases such as the BA15d used on bulbs like the 1157.
The 1156 conforms to ANSI standards and is recognized in both the United States and Canada, indicating a standardized specification rather than a proprietary or regional-only part.
Because the 1157 shares the same BA15s-style housing profile but carries a double-contact base and a dual-filament design, it is not a compatible substitute for the 1156 in the Corvair's back up light socket.