Ford F-350 Dome Light Bulb Size

The Ford F-350 dome light utilizes bulb sizes 912, 561, 105, 1003, and 81 depending on the specific production period for the vehicle. Provided information covers the span from 1953 through 1997 for the listed components.

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
1989-1997	912
1973-1980	561
1969-1972	105
1956-1968	1003
1953-1955	81

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	105
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1003
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 8W.	81

Other Locations

Additional Notes

The Ford F-350 dome light draws from four distinct bulb types across its model history: the 912 wedge, the 561 festoon, and three bayonet-base variants designated 105, 1003, and 81.
The 912 is a T15 wedge bulb rated at 12V and 12W. It is an ANSI-standardized type used in both the United States and Canada, and it is a variant of the 921 bulb.
The Ford F-350 uses the 912 bulb for the dome light across the 1989-1997 model years, making it the most frequently specified type in these data.
The 561 is a festoon-style bulb with a 44mm length and end-cap contacts, rated at 12V and 12W. Festoon bulbs seat by pressing between two spring clips rather than inserting into a socket, which makes them physically incompatible with wedge or bayonet housings.
The 561 festoon bulb is specified for the 1973-1980 model years.
The 105 and 1003 bulbs both use a BA15s single-contact bayonet base, meaning they share the same base type. However, the 105 is rated at 12V and 13W while the 1003 is rated at 12V and 21W, and the 105 is noted as a variant of the 1156. The wattage difference means these two types are not interchangeable despite the shared base style.
The 1003 is specified for the 1956-1968 model years, representing the longest consecutive span of any single bulb type in these data.
The 105 bulb is specified for the 1969-1972 model years.
The 81 bulb also uses a BA15s bayonet base but is rated at only 12V and 8W, the lowest wattage of any type listed. It is specified solely for the 1953-1955 model years.
Because the 912 wedge, 561 festoon, and BA15s bayonet types each require a physically different socket, bulbs from one category cannot be fitted into a housing designed for another, regardless of shared voltage ratings.