Mercury Tracer Back Up Light Bulb Size

The Mercury Tracer back up light utilizes bulb sizes 2456, P21W, and 1156 depending on the specific version. Data for the provided specifications covers the range from 1988 to 1999.

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
1997-1999	2456
1991-1992	1156
1988-1989	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, specialty application. 12V.	2456
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Mercury Tracer back up light specifications reference two distinct bulb types across its model years: the 2456 and the 1156.
The 1156 is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W, and carries ANSI standard recognition in both the US and Canada.
The BA15s bayonet base on the 1156 features a single contact pin, which is a defining characteristic that distinguishes it from double-contact bayonet variants and makes it non-interchangeable with those types.
The 2456 is a festoon bulb rated at 12V, designated for specialty applications, and also holds ANSI standard status in the US and Canada.
Festoon bulbs are cylindrical in form and make contact at each end rather than through a base, which means the 2456 and 1156 are physically incompatible and cannot substitute for one another.
The Mercury Tracer (1988-1989 and 1991-1992) uses the 1156 bulb for the back up light position.
The Mercury Tracer (1997-1999) uses the 2456 bulb for the back up light position.
The shift from the 1156 to the 2456 across Tracer model years reflects a change in socket and housing design, meaning parts from the earlier configuration are not transferable to the later one.