Plymouth Cricket Back Up Light Bulb Size

The Plymouth Cricket back up light utilizes 1156 and P21W bulb sizes for the rear illumination system. Data for the specific lighting components covers the range from 1971 to 1974.

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
1971-1974	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 Plymouth Cricket uses the 1156 bulb for the back up light across the 1971-1974 model years.
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 specifications shared across manufacturers.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is typical of incandescent automotive bulbs used in signaling and reversing light applications.
The bulb 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 would not be a correct substitute in this application.