Chevrolet Nova Back Up Light Bulb Size

The Chevrolet Nova back up light utilizes 1156 and P21W bulb sizes according to the provided technical specifications for the lighting system. Available data covers the range from 1969 through 1988 for the specified vehicle components.

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
1985-1988	1156
1969-1979	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 Nova uses the 1156 bulb for the back up light position across all listed model years from 1969 to 1979 and 1985 to 1988.
The 1156 is an ANSI-standardized bulb type, meaning its physical and electrical 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 incandescent automotive reverse light applications.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" designation indicates a single pin rather than the offset dual-pin arrangement found on related bulb types such as the 1157.
Because the 1156 is a single-filament bulb, it serves only one lighting function per socket, which is appropriate for a dedicated back up light application that does not require a secondary filament for a combined stop or tail function.
The BA15s base of the 1156 is not interchangeable with the BA15d base used on dual-filament bulbs, and substituting a dual-contact bulb into a single-contact socket would result in improper fitment.
The 1156 and the visually similar 1157 share the same 15mm bayonet collar width, but the pin configurations differ, making them physically incompatible despite their similar appearance.