Cadillac Calais Dome Light Bulb Size

The Cadillac Calais dome light utilizes bulb sizes 212-2, 1004, 90, and 161 depending on the specific production period. Available information covers the span from 1965 through 1976.

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
1976	212-2
1975	1004
1972-1973	90
1971	161
1965-1970	212-2

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, SV8.5 base. 12V, 12W.	212-2
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1004
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 13W.	90
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 1W.	161

Other Locations

Additional Notes

The 212-2 is the most frequently specified dome light bulb across the Cadillac Calais lineup, covering model years 1965-1970 and 1976.
The 212-2 is a festoon-type bulb with an SV8.5 base and a 41mm length, operating at 12V and 12W under the ANSI standard applicable to the US and Canada.
The festoon form factor of the 212-2 means it is held in place by spring-loaded end caps rather than a socket, a mounting method common in dome and map light housings of that era.
The bulb 90, specified for the Cadillac Calais in 1972-1973, is a single-filament type with a BA15s bayonet base, rated at 12V and 13W.
The BA15s base of the 90 bulb is a single-contact bayonet fitting, which is not interchangeable with dual-contact bayonet bases such as the BAY15d found on the 1004 bulb specified for the 1975 model year.
The 1004 bulb, used in the 1975 Cadillac Calais, is a dual-filament bulb with a BAY15d bayonet base rated at 12V and 21/5W, and it is noted as a variant of the 1157.
Despite the 1004 being a variant of the 1157, the two are not directly interchangeable in all applications due to differences in wattage ratings and intended circuit configurations.
The 161 bulb, specified for the 1971 Cadillac Calais, is a miniature wedge type in the T10 form factor, rated at only 12V and 1W, making it notably lower in output than the other bulb types listed across this model's history.
The T10 wedge base of the 161 bulb is physically incompatible with the bayonet and festoon mounting systems used by the other bulb types in these specifications, meaning housings are not shared across those model years.
All four bulb types across these specifications conform to ANSI standards recognized in both the US and Canada.