Lincoln Cosmopolitan Dome Light Bulb Size

The Lincoln Cosmopolitan dome light utilizes bulb size 63 and bulb size 81 for interior illumination. Data for the specific components covers the period from 1950 through 1954.

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
1953-1954	63
1952	81
1950-1951	63

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 0.63W.	63
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 8W.	81

Other Locations

Additional Notes

The bulb 63 is the most frequently specified dome light bulb across the Lincoln Cosmopolitan fitment data, appearing in the 1950-1951 and 1953-1954 model years.
The bulb 63 is an ANSI-standard single-filament bulb rated at 12V and 0.63W, fitted with a BA9s base, which is a miniature pin-type base common in low-current interior lighting applications.
The bulb 81 is an ANSI-standard single-filament bulb rated at 12V and 8W, fitted with a BA15s bayonet base, a single-contact bayonet mount typically associated with higher-wattage interior or signal lamp applications.
The 1952 Lincoln Cosmopolitan dome light takes the bulb 81, which draws significantly more wattage than the bulb 63 used in surrounding model years.
The BA9s base of the bulb 63 and the BA15s base of the bulb 81 are physically incompatible, meaning the two bulb types are not interchangeable despite both operating on a 12V system.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating standardized construction and base tolerances across those markets.
The single-filament design of both bulbs reflects their use in a non-switching interior application such as a dome light, where only one brightness level is required.