Jeep J10 Back Up Light Bulb Size

The Jeep J10 back up light utilizes 1156, P21W, and 199 bulb sizes depending on the specific production requirements for the vehicle. Data for the lighting components covers the range from 1974 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
1976-1988	1156
1975	199
1974	1156

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. Variant of 1156. 12V, 21W.	199

Other Locations

Additional Notes

The Jeep J10 backup light bulb specifications cover model years 1974 through 1988, with two distinct bulb sizes appearing across that range.
The 1156 bulb is the dominant fitment for the Jeep J10, appearing in all listed model years except 1975.
The 1156 is an ANSI-standard single-filament bulb rated at 12 volts and 21 watts, mounted via a BA15s bayonet base.
A BA15s bayonet base uses a single contact pin offset to one side, which mechanically prevents incorrect bulb orientation during installation.
The 1975 Jeep J10 uses the 199 bulb rather than the 1156, making it the sole exception across the entire model range covered by these specifications.
The 199 is also an ANSI-standard single-filament bulb sharing the same 12-volt, 21-watt rating and BA15s bayonet base as the 1156, and is classified as a variant of it.
Despite their shared electrical and base specifications, the 199 and 1156 are listed as separate part numbers under ANSI standards, and their fitment is not interchangeable across all model years according to these specifications.
The single-filament design of both bulb types indicates they serve a dedicated function, consistent with backup lighting, which operates independently rather than sharing a filament with another circuit such as a brake or tail light.