Mercury Marquis Dome Light Bulb Size

The Mercury Marquis dome light utilizes bulb sizes 906, 912, 105, 211-2, 561, 1003, and 1816 across various production periods. Available information covers the span from 1967 through 1986.

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
1983-1986	906
1982	912
1981	105
1980	906
1977-1979	211-2
1976	561
1975	211-2
1972-1974	561
1970-1971	105
1968-1969	1003
1967	1816

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 8W.	906
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	105
ANSI standard (US & Canada). Festoon bulb, 41mm length, SV8.5 base. 12V, 12W.	211-2
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. 12V, 21W.	1003
ANSI standard (US & Canada). Miniature wedge bulb (T3.25). 12V, 4W.	1816

Other Locations

Additional Notes

The Mercury Marquis dome light specifications span the 1967-1986 model years, covering seven distinct bulb sizes across that range.
The 211-2 is the most frequently specified bulb across the Mercury Marquis dome light fitments, appearing in five model years: 1975, and 1977-1979. It is a festoon-type bulb with a 41mm length and an SV8.5 base, rated at 12V and 12W.
The 906 is the second most common bulb in these specifications, covering four model years from 1983-1986, as well as 1980. It is a T10 miniature wedge bulb rated at 12V and 8W.
The 561 festoon bulb is specified for the Mercury Marquis in 1972-1974 and 1976. Although it shares the same 12V and 12W electrical rating as the 211-2, it has a 44mm length and uses end-cap contacts rather than an SV8.5 base, making the two festoon types non-interchangeable.
The 105 bulb is specified for 1970-1971 and 1981. It uses a BA15s bayonet base and is rated at 12V and 13W. It is a variant of the 1156, though the two are not identical and should not be treated as direct substitutes without verification.
The 1003 bulb, specified for 1968-1969, also uses a BA15s bayonet base but is rated at a notably higher 21W output compared to the 105. Despite sharing the same base type, the significant wattage difference means the two bulbs serve different lighting demands and are not interchangeable.
The 912 wedge bulb is specified exclusively for the 1982 Mercury Marquis. It is a T15 wedge type rated at 12V and 12W and is noted as a variant of the 921, though the two are distinct part numbers.
The 1816 miniature wedge bulb is specified only for the 1967 model year. At 12V and 4W, it carries the lowest wattage of any bulb in these specifications. Its T3.25 form factor differs from the T10 of the 906, and the two wedge types are not interchangeable.
Several bulb types in these specifications share the same voltage and wattage ratings yet use different base types, such as the 211-2 and 912, both rated at 12V and 12W. Electrical compatibility alone does not indicate physical interchangeability, as base type and form factor govern fitment.
All seven bulb sizes listed in these specifications conform to ANSI standards applicable in both the United States and Canada.