White WIL Back Up Light Bulb Size

The White WIL back up light utilizes a single 1156 bulb size for illumination across all recorded vehicle applications within the provided technical data set. Available information spans a chronological range from 1984 through 1988.

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
1984-1988	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 listed for the back up light across all recorded model years of the White WIL, covering 1984-1988.
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 standards shared across those markets.
It operates on a 12-volt system and draws 21 watts, which is typical of incandescent automotive bulbs used in signaling and reversing light applications.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, distinguishing it from double-contact variants such as the 1157.
Because the BA15s base has only one contact pin, the 1156 carries a single filament, making it unsuitable as a direct substitute in sockets designed for dual-filament bulbs that serve combined stop and tail functions.
The consistent use of the 1156 across the full 1984-1988 span of the White WIL indicates no change in back up light socket specification during that period, which supports straightforward parts interchangeability within those years.