Volvo WI Back Up Light Bulb Size

The Volvo WI back up light requires bulb size 1156 or P21W depending on the specific configuration of the vehicle. Data for the provided specifications covers the range from 1996 to 1998.

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
1996-1998	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 1156 is the sole bulb type listed for the Volvo WI backup light across the 1996-1998 model years.
The 1156 is an ANSI-standardized bulb recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical parameters shared across many vehicle applications.
It is a single-filament bulb, which is typical for functions requiring only one lighting state, such as a backup light that is either on or off.
The 1156 uses a BA15s bayonet base, a single-contact mount where the bulb is inserted and rotated to lock into place rather than threaded.
The bulb operates at 12 volts and draws 21 watts, consistent with standard automotive electrical systems.
The BA15s designation indicates a single-contact bayonet fitting, and substituting a dual-contact variant such as the BA15d would result in an incompatible fitment despite a similar physical profile.