White WCS Back Up Light Bulb Size

The White WCS back up light utilizes a 1156 bulb size for illumination purposes across all recorded vehicle applications within the provided technical data set. Available information covers a specific range of production from 1981 through 1988 for the specified component.

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
1981-1988	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 specified for the back up light across all listed model years of the White WCS, covering 1981-1988.
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 tolerances shared across manufacturers.
The 1156 operates on a 12-volt circuit and draws 21 watts, which is typical of incandescent automotive bulbs used in reverse light applications.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, as opposed to the dual-pin BA15d variant. These two base types are not interchangeable despite sharing the same 15mm collar width.
The 1156 is a single-filament bulb, meaning it serves one lighting function only. This distinguishes it from dual-filament types such as the 1157, which handles two functions through separate filaments within the same envelope.
Because the BA15s base is a single-contact design, substituting a dual-contact bayonet bulb in the same socket would result in an improper fit and potential circuit fault.