Ford Windstar Dome Light Bulb Size

The Ford Windstar dome light utilizes unique bulb sizes 906, 921, 578, and 912 depending on the specific version of the vehicle. Available data covers the range from 1995 through 2003.

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
2003	906
2002	921
2001	578
2000	921
1999	906
1995-1998	912

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
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V, 12W.	578
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912

Other Locations

Additional Notes

The Ford Windstar dome light draws from four distinct bulb types across its production run: the 906, 921, 578, and 912, each carrying a different wattage and physical format.
The 912 bulb is the most frequently specified type in these records, covering the 1995-1998 model years. It is a T15 wedge bulb rated at 12V and 12W, and it is formally classified as a variant of the 921.
Although the 912 and 921 share the same T15 wedge form factor and 12V operating voltage, they differ in wattage. The 912 draws 12W while the 921 draws 16W, meaning the two are not directly interchangeable despite their physical similarity.
The 921 is specified for the 2000 and 2002 Ford Windstar. At 16W, it is the highest-wattage bulb in this set of specifications.
The 906 is a T10 miniature wedge bulb rated at 12V and 8W. It is the lowest-wattage type listed and is specified for the 1999 and 2003 model years.
The 2001 Ford Windstar is the only model year in these specifications to use the 578 bulb. Unlike the wedge-type bulbs used in other years, the 578 is a festoon bulb with a 41mm length and end-cap contacts, representing a physically distinct mounting style.
Because the 578 uses end-cap contacts rather than a wedge base, it is not interchangeable with any of the other three bulb types listed, regardless of voltage or wattage compatibility.
All four bulb types in these specifications conform to ANSI standards recognized in both the United States and Canada.
The dome light bulb specification changes across several consecutive model years, indicating that the same socket configuration was not retained throughout the entire production run of the Windstar.