Ford E-350 Back Up Light Bulb Size

The Ford E-350 back up light bulb size chart specifies 3 distinct bulb sizes: 2456, 2356, and 3156 for this vehicle model. The replacement chart contains data covering 1975 through 1998 vehicle production years.

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
1997-1998	2456
1996	2356
1994-1995	2456
1993	2356
1992	3156
1975-1991	1156

Bulb Specifications

Description	Bulb Size
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 wedge bulb (T25). 12V, 27W.	3156
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Ford E-350 back up light bulb specifications span model years 1975 through 1998, covering four distinct ANSI-standard bulb types across that range.
The 1156 bulb is the most frequently specified type, covering the Ford E-350 from 1975 through 1991. It is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W.
The BA15s bayonet base on the 1156 is a single-contact design, meaning it is not interchangeable with dual-contact bayonet bases found on other bulb types in these specifications.
The 3156 bulb is specified for the 1992 Ford E-350. It is a single-filament wedge-type bulb in a T25 form factor, rated at 12V and 27W, and uses a wedge base rather than a bayonet fitting.
Because the 1992 model year uses a wedge-base 3156 while the surrounding years use bayonet-base bulbs, the 3156 is not a drop-in replacement for the 1156 used in earlier model years.
The 2356 bulb is specified for the 1993 and 1996 model years. It features a dual-filament design with a BAY15d bayonet base, which has two contact pins offset at different heights to prevent incorrect installation.
The dual-filament construction of the 2356 distinguishes it from the single-filament 1156 and 3156 bulbs, making cross-substitution between these types technically incompatible without socket modification.
The 2456 bulb is specified for the 1994-1995 and 1997-1998 model years. It is classified as a festoon bulb intended for specialty applications, operating at 12V.
A festoon bulb, such as the 2456, uses end-cap contacts rather than a bayonet or wedge base, making it physically distinct from all other bulb types listed in these specifications.
The back up light bulb type for the Ford E-350 changed multiple times between 1991 and 1998, transitioning across wedge, bayonet, and festoon base configurations, which means fitment verification by model year is necessary before replacement.