Nissan 720 Back Up Light Bulb Size

The Nissan 720 back up light uses bulb size 1156 or P21W depending on the specific version of the vehicle. Data for the bulb size covers the range from 1983 to 1986.

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
1983-1986	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 Nissan 720 uses the 1156 bulb for the back up light position across the 1983-1986 model years.
The 1156 is an ANSI-standardized bulb type, meaning its physical and electrical specifications are governed by a recognized North American standard used 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 automotive incandescent output for reverse lighting applications.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, as opposed to dual-filament types that handle two functions such as braking and running light simultaneously.
The 1156 uses a BA15s bayonet base, where "BA15s" denotes a single-contact bayonet fitting with a 15mm base width. The single-contact design is directly tied to the bulb's single-filament construction.
The BA15s base type is not interchangeable with the BA15d base, which is a dual-contact variant. Substituting a dual-contact bulb into a single-contact socket is not mechanically compatible.