Mercury Monterey License Plate Bulb Size

The Mercury Monterey license plate light uses unique bulb sizes 12961, 90, 631, 97, 1155, 67, and 63. Available data for the specified vehicle covers the range from 1950 to 2007.

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
2004-2007	12961
1973-1974	90
1972	631
1968-1971	97
1963-1967	1155
1956-1962	67
1950-1955	63

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 13W.	90
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W.	631
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	97
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W.	1155
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 8W.	67
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 0.63W.	63

Other Locations

Additional Notes

The Mercury Monterey license plate bulb specifications span from 1950 to 2007, with six distinct bulb types used across that period: 63, 67, 1155, 97, 631, 90, and 12961.
The bulb 67 is the most frequently specified type in the Mercury Monterey's license plate fitment data, covering model years 1956-1962. It is an ANSI-standard single-filament bulb with a BA15s bayonet base rated at 12V and 8W.
The bulb 63, used on the Mercury Monterey from 1950-1955, operates at a notably low 0.63W and uses a BA9s base, which is physically smaller than the BA15s base found on most other bulbs in these specifications. The BA9s and BA15s bases are not interchangeable.
The 2004-2007 Mercury Monterey uses the Philips 12961, a T10 miniature wedge bulb with a W2.1x9.5d base rated at 12V and 5W. The wedge base design is mechanically distinct from the bayonet bases used in all earlier Monterey license plate bulb fitments, making cross-era substitution incompatible.
Bulbs 97, 631, and 1155 are all described as variants of the 1156 with a shared BA15s bayonet base, yet they differ in wattage. The 97 is rated at 13W, while both the 631 and 1155 are rated at 21W. Despite the shared base type, wattage differences may affect socket compatibility and circuit load.
The bulb 90, specified for the 1973-1974 Monterey, shares the BA15s bayonet base with bulbs 97, 631, and 1155, but it is not classified as a variant of the 1156. It is rated at 13W, the same wattage as the 97 used in 1968-1971.
The 1972 Monterey uses the 631, rated at 21W, which places it among the higher-wattage fitments in the license plate specifications. The adjacent model years 1968-1971 use the 97 at 13W, and 1973-1974 use the 90 at 13W, meaning the 1972 specification represents a wattage increase relative to both surrounding years.
The 1963-1967 Monterey uses the 1155, a BA15s single-filament bulb rated at 21W. This is the same wattage as the 631 used in 1972, though the two are separate ANSI designations and are not listed as interchangeable in the specifications.