Ford E-250 Dome Light Bulb Size

Additional Notes

• The Ford E-250 dome light uses five distinct bulb sizes across its model years: 912, 578, 6411, 214-2, and 561.
• The 912 is a T15 wedge bulb rated at 12V and 12W. It is the most frequently specified bulb in the Ford E-250 dome light application, covering the 1995-2003 and 2008-2014 model years.
• The wedge base of the 912 differs structurally from the festoon-style bases used by all other bulbs in these specifications. The 912 is also noted as a variant of the 921 bulb.
• The 578, 6411, 214-2, and 561 are all festoon-type bulbs, meaning they seat between two end contacts within a cylindrical housing rather than inserting into a socket.
• Despite sharing the festoon form factor, these four bulbs are not interchangeable. They differ in length and base type, which affects physical fit within the dome light housing.
• The 578 and 214-2 are both 41mm festoon bulbs rated at 12V and 12W, but they use different base contacts. The 578 uses end-cap contacts while the 214-2 uses an SV8.5 base, making them incompatible despite identical length and wattage ratings.
• The 6411 is a 36mm festoon bulb with an SV8.5 base rated at 12V and 5W, making it the lowest-wattage bulb in these specifications. Its shorter length distinguishes it from the 214-2, which shares the same base type.
• The 561 is a 44mm festoon bulb with end-cap contacts rated at 12V and 12W. It is the longest festoon bulb in these specifications and was used on the Ford E-250 from 1975-1980.
• All five bulb sizes conform to ANSI standards applicable in both the United States and Canada.
• The Ford E-250 (2006-2007) uses the 578 bulb, which sits between model year groups specifying the 912, representing a direct socket-type change that requires attention when sourcing a replacement.