Plymouth Neon Back Up Light Bulb Size

Plymouth Neon back up light bulbs utilize 921 and 3157 bulb sizes for this model. The replacement chart covers vehicle production years spanning 1995 to 2001.

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
2000-2001	921
1995-1999	3157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157

Other Locations

Additional Notes

The Plymouth Neon back up light specifications cover model years 1995-2001 and reference two distinct bulb types: the 921 and the 3157.
The 921 bulb is an ANSI-standard wedge type in a T15 form factor, rated at 12 volts and 16 watts, with a single filament.
The 3157 bulb is also an ANSI-standard wedge type, housed in a T25 form factor, and operates on a dual-filament design rated at 12 volts with a 27-watt primary filament and a 7-watt secondary filament.
The Plymouth Neon (2000-2001) uses the 921 bulb for the back up light position.
Model years 1995-1999 use the 3157 bulb instead, making the two bulb types non-interchangeable across the full production span of this vehicle.
The dual-filament construction of the 3157 means it carries two separate circuits within a single bulb, a characteristic absent in the single-filament 921.
The wattage difference between the two bulbs is notable: the 921 draws 16 watts, while the 3157 draws up to 27 watts on its primary filament, reflecting a meaningful difference in electrical load on the vehicle's circuit.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating standardized base and electrical ratings across those markets.
The T15 and T25 designations refer to the tubular wedge base sizing of each bulb, and these sizes are not physically interchangeable with one another.
Installing a 3157 in a socket designed for a 921 would present a fitment conflict due to the differing base sizes and wattage ratings.