Plymouth Duster Back Up Light Bulb Size

The Plymouth Duster back up light requires bulb size P21W or 1156 depending on the specific version of the component. Data for the bulb sizes covers the range from 1970 to 1976.

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
1970-1976	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 Duster uses the 1156 bulb for the back up light across all listed model years, spanning 1970-1976.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, which in this application is the back up light.
The 1156 operates at 12 volts and 21 watts, placing it in the standard range for automotive reverse lighting.
The 1156 uses a BA15s bayonet base, a single-contact mount where the bulb is inserted and twisted to lock into the socket.
The BA15s base is not interchangeable with the BA15d base, which is a dual-contact variant used on twin-filament bulbs such as the 1157.
The 1156 is an ANSI-standardized bulb recognized in both the United States and Canada, indicating consistent specifications across North American markets.