Jeep J-4500 Back Up Light Bulb Size

The Jeep J-4500 back up light uses a 1156 bulb size for this model. The replacement chart covers 1972 to 1973 production years with corresponding bulb size 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
1972-1973	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 Jeep J-4500 backup light across both documented model years, 1972-1973.
The 1156 operates on a 12-volt electrical system and draws 21 watts, placing it in the standard range for single-circuit automotive lighting applications.
As a single-filament bulb, the 1156 serves one dedicated function per socket, which aligns with its role in a backup light application where only one lighting state is required.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, distinguishing it from the dual-contact BA15d base used in other automotive bulbs.
The 1156 carries ANSI standardization recognized in both the United States and Canada, meaning the bulb conforms to a defined set of electrical and physical tolerances shared across compliant manufacturers.
The BA15s bayonet mount is not interchangeable with BA15d sockets due to the difference in contact configuration, and substituting one for the other risks improper seating or electrical failure.