Cadillac Brougham Dome Light Bulb Size

The Cadillac Brougham dome light requires 561 and 912 bulb sizes depending on the specific application for the interior illumination system. Data for the bulb sizes covers the range from 1988 to 1992.

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
1992	912
1990-1991	561
1988-1989	912

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561

Other Locations

Additional Notes

The Cadillac Brougham dome light uses two distinct bulb types across its 1988-1992 model years: the 912 and the 561.
The 912 is an ANSI-standard wedge bulb classified under the T15 designation, operating at 12 volts and 12 watts.
The 912 is a variant of the 921 bulb. While the two share a close relationship, they are not unconditionally interchangeable in all applications.
The 561 is an ANSI-standard festoon bulb with a 44mm length and end-cap contacts, also rated at 12 volts and 12 watts.
Festoon bulbs seat by pressing lengthwise between two spring clips, a mounting method that differs fundamentally from the wedge-style socket used by the 912.
The 1990-1991 Cadillac Brougham specifies the 561 festoon bulb for the dome light position.
The 912 wedge bulb is specified for the 1988-1989 and 1992 model years.
Because the 912 and 561 use physically incompatible socket types, one cannot be substituted for the other regardless of their identical voltage and wattage ratings.