Buick Electra Back Up Light Bulb Size

The Buick Electra back up light utilizes 1156, P21W, and 1073 bulb sizes for the rear illumination system. Available information for the specified vehicle covers the range from 1959 through 1990.

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
1990	1156
1963-1986	1156
1962	1073
1961	1156
1959-1960	1073

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	1073

Other Locations

Additional Notes

The back up light bulb specifications for the Buick Electra span model years 1959 through 1990, with a gap at 1987-1989.
The 1156 bulb is the dominant fitment across this range, appearing in the vast majority of model years covered by these specifications.
The 1156 is an ANSI-standard single-filament bulb rated at 12 volts and 21 watts, mounted via a BA15s bayonet base.
The BA15s bayonet base features a single contact pin, which is a defining characteristic of single-filament automotive bulbs in this family.
The 1073 bulb appears in the Buick Electra for model years 1959, 1960, and 1962, making it a less common fitment within these specifications.
The 1073 is also an ANSI-standard single-filament bulb with a BA15s bayonet base, rated at 12 volts but drawing only 13 watts, making it a lower-wattage variant compared to the 1156.
Although the 1156 and 1073 share the same BA15s bayonet base, they are not interchangeable due to their differing wattage ratings, which affect light output and circuit load.
The model year 1961 uses the 1156 rather than the 1073, distinguishing it from the adjacent 1960 and 1962 entries that specify the lower-wattage bulb.