Lincoln Mark VIII Dome Light Bulb Size

The Lincoln Mark VIII dome light requires a 906 or 921 bulb size depending on the specific version of the vehicle. Data for the lighting components covers the range from 1993 to 1998.

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
1994-1998	906
1993	921

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 8W.	906
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

Other Locations

Additional Notes

The Lincoln Mark VIII uses two distinct bulb sizes for the dome light across its production run: the 906 and the 921.
The 906 bulb is an ANSI-standard miniature wedge type with a T10 form factor, rated at 12V and 8W.
The 921 bulb shares the same ANSI-standard classification and voltage rating of 12V but carries a higher wattage of 16W and uses a larger T15 wedge form factor.
The 1994-1998 Lincoln Mark VIII dome light takes the 906 bulb, while the 1993 model year uses the 921.
Because the 906 and 921 differ in both physical size and wattage, they are not interchangeable despite both being wedge-type bulbs rated at 12V.
The T15 form factor of the 921 is physically larger than the T10 of the 906, which means a 921 bulb would not seat correctly in a socket designed for the 906.
The wattage difference between the two bulbs is significant: the 921 draws twice the power of the 906, which is a relevant consideration when substituting LED equivalents rated by original wattage.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating standardized base and filament specifications across those markets.