Ford Taurus Back Up Light Bulb Size

The Ford Taurus back up light utilizes bulb sizes 921, 12184, 7440, 2456, 2356, P21W, and 1156. Available information covers the span from 1986 through 2019.

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
2013-2019	921
2011-2012	12184
2010	7440
2006-2009	921
1998-1999	2456
1996-1997	2356
1992	2356
1991	2456
1990	2356
1989	2456
1988	1156
1986	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
Philips part number. Halogen bulb, specialty application. 12V.	12184
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440
ANSI standard (US & Canada). Festoon bulb, specialty application. 12V.	2456
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V.	2356
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The 921 is the most frequently specified back up light bulb across the Ford Taurus lineup, appearing in model years 2006-2009 and 2013-2019. It is a T15 wedge-base bulb rated at 12V and 16W under the ANSI standard used in the US and Canada.
The 7440 is a T20 single-filament wedge bulb rated at 12V and 21W. The Ford Taurus (2010) uses this bulb for the back up light, making it the sole model year in the specifications with this fitment.
The 12184 is a Philips part number rather than an ANSI standard designation, classifying it as a specialty halogen bulb rated at 12V. The Ford Taurus uses this bulb for the 2011-2012 model years.
The 921 and 7440 both use wedge-style bases, but they are not interchangeable. The 921 uses a T15 body while the 7440 uses a larger T20 body, and their wattage ratings also differ at 16W and 21W respectively.
The 2356 is a dual-filament bulb with a BAY15d bayonet base, rated at 12V. Despite having two filaments, it is specified here strictly for the back up light function in model years 1990, 1992, and 1996-1997.
The 2456 is a festoon-style bulb rated at 12V and is designated as a specialty application under the ANSI standard. It is specified for the 1989, 1991, and 1998-1999 model years.
The 1156 is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W. It is specified for the 1986 and 1988 model years, making it the oldest bulb type in these specifications.
The BAY15d base on the 2356 and the BA15s base on the 1156 are both bayonet-style mounts, but they are not interchangeable. The BAY15d base has offset pins to accommodate dual-filament wiring, while the BA15s base has symmetrical pins suited to a single-filament circuit.
The wedge-base bulbs such as the 921 and 7440 rely on the bulb's own glass and lead wires to make contact with the socket, whereas the bayonet-base bulbs used in earlier Taurus model years require a twist-lock socket with pin contacts.
Across the full span of these specifications, six distinct bulb types are noted for the back up light position, reflecting changes in socket design and bulb technology across different generations of the Ford Taurus.