Mercury Colony Park Dome Light Bulb Size

The Mercury Colony Park dome light utilizes bulb sizes 561, 906, 912, 105, 1003, and 1816 across various production periods. Available data covers the span from 1957 through 1991.

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
1991	561
1990	906
1987-1989	912
1972-1974	561
1970-1971	105
1968-1969	1003
1967	1816
1957-1966	1003

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561
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). 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 Colony Park dome light specifications span model years 1957 through 1991, with six distinct bulb sizes used across that period: 561, 906, 912, 105, 1003, and 1816.
The 1003 bulb is the most frequently specified size in the Mercury Colony Park dome light fitment data, covering model years 1957-1966 and 1968-1969. It is a single-filament bulb with a BA15s bayonet base rated at 12V and 21W.
The 912 bulb is specified for the Mercury Colony Park for model years 1987-1989. It is a T15 wedge-base bulb rated at 12V and 12W, and it is a variant of the 921 bulb type.
Because the 912 and 921 are variants of each other, substitution between them is a known consideration in automotive lighting, though the specifications list only the 912 for those model years.
The 561 festoon bulb, specified for 1972-1974 and 1991, uses end-cap contacts rather than a wedge or bayonet base. At 44mm in length, it sits in a holder that makes contact at both ends of the bulb body.
The 906 bulb, specified solely for the 1990 model year, is a T10 miniature wedge type rated at 8W, making it the lowest-wattage bulb in the Colony Park dome light specifications.
The 105 bulb, specified for 1970-1971, shares the BA15s bayonet base with the 1003 but is rated at 13W rather than 21W. It is a variant of the 1156 bulb type, and the wattage difference means the two are not directly interchangeable despite the shared base style.
The 1816 bulb is specified exclusively for the 1967 Mercury Colony Park. As a T3.25 miniature wedge type rated at only 4W, it is the smallest and lowest-output bulb in the entire Colony Park dome light fitment range.
All six bulb types in the specifications conform to ANSI standards applicable in both the United States and Canada, indicating standardized electrical and physical ratings across the full range of listed sizes.
The base type changes across the model year range represent a fitment incompatibility: bayonet-base bulbs (105, 1003), festoon end-cap bulbs (561), and wedge-base bulbs (906, 912, 1816) each require a physically different socket, meaning cross-era substitution is not possible without socket modification.