Ford Probe Back Up Light Bulb Size

The Ford Probe back up light utilizes 1156, 1157, and P21W bulb sizes according to the provided specifications for the vehicle. Data for the lighting components covers the range from 1989 to 1997.

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
1992-1997	1156
1989-1991	1157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157

Other Locations

Additional Notes

The Ford Probe uses two distinct bulb types across its model years for the back up light: the 1156 for 1992-1997 and the 1157 for 1989-1991.
Both the 1156 and 1157 are ANSI standardized bulbs recognized in the United States and Canada.
The 1156 is a single-filament bulb rated at 12V and 21W, mounted on a BA15s bayonet base.
The 1157 is a dual-filament bulb rated at 12V with filaments drawing 21W and 5W respectively, mounted on a BAY15d bayonet base.
Although both bulbs share the same 12V operating voltage and a 21W primary filament rating, they are not interchangeable due to their different base designs.
The BA15s base of the 1156 has a single contact pin, while the BAY15d base of the 1157 has two offset contact pins to support its dual-filament configuration.
The physical difference in base design between the 1156 and 1157 prevents accidental cross-installation, as the offset pins of the BAY15d base will not seat correctly in a BA15s socket.
The shift from the dual-filament 1157 to the single-filament 1156 in the Ford Probe (1992) reflects a change in back up light socket design between the first and second generations of the vehicle.