Plymouth Sundance Back Up Light Bulb Size

The Plymouth Sundance back up light utilizes 1156, 921, and P21W bulb sizes depending on the specific production period for the vehicle. Data for the bulb sizes covers the range from 1987 through 1994.

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
1993-1994	1156
1992	921
1987-1991	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

Other Locations

Additional Notes

The Plymouth Sundance back up light specifications cover model years 1987-1994.
The 1156 bulb is the predominant back up light fitment across the Plymouth Sundance lineup, appearing in seven of the eight model years covered by the specifications.
The 1156 is a single-filament bulb rated at 12V and 21W, built to ANSI standards recognized in both the United States and Canada. It uses a BA15s bayonet base, which is a single-contact bayonet mount with a 15mm base width.
The 1992 Plymouth Sundance is the sole model year specified with the 921 bulb rather than the 1156.
The 921 is a wedge-type bulb in the T15 form factor, rated at 12V and 16W, and also meets ANSI standards for the US and Canadian markets. A wedge base relies on the tension of its wire contacts rather than a bayonet locking mechanism for retention.
The 921 operates at 16W compared to the 21W rating of the 1156, meaning the two bulbs are not electrically equivalent and are not interchangeable despite both being 12V single-filament designs.
The differing base types, a BA15s bayonet for the 1156 and a wedge mount for the 921, also make the two bulbs physically incompatible with each other's sockets.
Model years 1987-1991 and 1993-1994 all share the 1156 specification, which means the same bulb fits across those years without modification.