Ford F-150 Map Light Bulb Size

The Ford F-150 Map Light utilizes bulb sizes 12961, 194, 906, 578, and 105 depending on the specific production period. Available data covers the range from 1985 through 2014.

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
2013-2014	12961
2006-2012	194
2004-2005	906
1997-1998	578
1988-1996	105
1985-1986	105

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 8W.	906
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V, 12W.	578
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	105

Other Locations

Additional Notes

The Ford F-150 map light draws from four distinct bulb types across its model years: the T10 wedge family (bulbs 12961, 194, and 906), the 578 festoon, and the 105 bayonet. The T10 wedge format is the most frequently specified, covering the 2006-2014 model years.
The 194 bulb is an ANSI-standard T10 miniature wedge rated at 12V and 3.78W. It is the single most recurring map light specification for the Ford F-150, appearing across the 2006-2012 model years.
The 12961 is a Philips-branded T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W. It is specified for the 2013-2014 F-150 and carries a manufacturer part number rather than an ANSI designation, which distinguishes it from the otherwise interchangeable 194 in physical format.
Although the 194 and 12961 share the T10 wedge form factor and the same W2.1x9.5d base type, their wattage ratings differ. The 194 draws 3.78W while the 12961 draws 5W, a distinction relevant to socket heat tolerance and circuit load.
The 906 is an ANSI-standard T10 miniature wedge rated at 12V and 8W, specified for the 2004-2005 F-150. Its wattage is more than double that of the 194, meaning the two are not considered interchangeable despite sharing the same wedge base format.
The 578 is a festoon-style bulb rated at 12V and 12W, with a 41mm length and end-cap contacts. This construction differs fundamentally from the wedge and bayonet types, as it is held in place by spring clips rather than inserted into a socket. It is specified for the 1997-1998 F-150.
The 105 is an ANSI-standard single-filament bulb with a BA15s bayonet base, rated at 12V and 13W. It is described as a variant of the 1156 and is the highest-wattage map light bulb in these specifications. It is listed for the Ford F-150 across the 1985-1996 model years, with the exception of 1987.
The BA15s bayonet base of the 105 bulb is mechanically incompatible with the wedge sockets used by the 194, 12961, and 906 bulbs. Substitution between these types is not possible without a socket adapter.
The 578 festoon bulb's end-cap contact design is also mechanically incompatible with both the wedge and bayonet socket types present in other F-150 model years, making cross-type substitution equally impractical without hardware modification.
All five bulb types specified operate at 12V, which is consistent with standard automotive electrical systems. Their wattage ratings, however, range from 3.78W to 13W, meaning socket and circuit ratings are relevant factors when a replacement bulb is being selected.