Buick LeSabre Dome Light Bulb Size

Additional Notes

• The Buick LeSabre dome light specifications span model years 1959 through 2005, covering four decades of production and referencing nine distinct bulb sizes across that period.
• The 561 bulb is the most frequently specified size in these records, covering the LeSabre from 1974 through 1987. It is a festoon-type bulb with a 44mm length, end-cap contacts, and a 12V, 12W rating under the ANSI standard.
• The 578 bulb is specified for the Buick LeSabre from 2000 through 2005. Like the 561, it is a festoon-type bulb with end-cap contacts rated at 12V and 12W, though its length is 41mm rather than 44mm, making the two types physically non-interchangeable despite identical wattage ratings.
• The 211-2 bulb also shares the 41mm festoon length and 12V, 12W rating with the 578, but uses an SV8.5 base rather than end-cap contacts. This base difference means the 211-2 and 578 are not interchangeable even though their electrical ratings are identical.
• The 1004 bulb is specified across several non-consecutive model years from 1959 through 1968. It is a dual-filament bulb with a BAY15d bayonet base, rated at 12V and 21/5W, and is classified as a variant of the 1157 bulb type.
• The 906 and 168 bulbs are both T10 miniature wedge types operating at 12V, but they differ in wattage. The 906 is rated at 8W and is specified for the 1997-1998 model years, while the 168 is rated at 4.9W and is specified for 1992-1996 model years. The wattage difference means they are not electrically equivalent substitutes.
• The 194 bulb, specified for the 1971 model year, is also a T10 miniature wedge type at 12V but carries a lower wattage of 3.78W compared to both the 906 and 168, placing it at the lower end of the T10 wattage range present in these specifications.
• The 89 and 90 bulbs, specified for the 1970 and 1960 model years respectively, both use a BA15s single-contact bayonet base and share a 12V, 13W rating. The BA15s base is a single-filament bayonet mount, distinguishing these bulbs from the dual-filament BAY15d base used by the 1004.
• Festoon-type bulbs, which include the 578, 561, and 211-2, rely on physical length and base type for fitment. Because the 561 is 3mm longer than the 578 and 211-2, substituting one festoon type for another without confirming both length and base type would result in an incorrect fit.
• All bulb sizes listed in these specifications conform to the ANSI standard applicable to the United States and Canada, indicating that the sizing designations follow a standardized North American classification system.