Jeep CJ3 Back Up Light Bulb Size

The Jeep CJ3 back up light uses a 1156 bulb size for this model. The replacement chart covers 1959 to 1966 production years with corresponding bulb specifications.

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
1959-1966	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 across all model years in the Jeep CJ3 back up light specifications.
The 1156 is a single-filament bulb, meaning it serves one lighting function rather than combining two, such as stop and tail duties, into a shared unit.
It operates on a 12-volt electrical system and draws 21 watts.
The 1156 follows the ANSI standard, which applies to both the United States and Canada.
Its base type is the BA15s bayonet mount, a single-contact design that locks into the socket with a twist rather than a threaded connection.
The Jeep CJ3 back up light specifications cover the 1959-1966 model years, all of which share the same 1156 bulb fitment.
Because the BA15s base is a single-contact bayonet, it is not interchangeable with the BA15d, which is a dual-contact variant used in some other automotive applications.