Lincoln Town Car Map Light Bulb Size

Additional Notes

• The Lincoln Town Car map light uses four distinct bulb types across its production span: the 578, 211-2, 912, and 105.
• The 578 is a festoon-style bulb rated at 12V and 12W, with a 41mm length and end-cap contacts. It fits the Lincoln Town Car for model years 1998-2011.
• The 211-2 is also a festoon-style bulb rated at 12V and 12W, sharing the same 41mm length as the 578 but using an SV8.5 base rather than end-cap contacts. It fits the 1990-1991 and 1995-1997 model years.
• Although the 578 and 211-2 share the same voltage, wattage, and physical length, their base types differ, making them non-interchangeable without confirming socket compatibility.
• The 912 is a T15 wedge bulb rated at 12V and 12W. It is a variant of the 921 bulb and fits the 1992-1994 and 1983 model years.
• The 105 is a single-filament bulb with a BA15s bayonet base, rated at 12V and 13W. It is a variant of the 1156 and fits the 1981-1982 and 1984-1989 model years.
• The 105 is the only map light bulb in these specifications rated at 13W rather than 12W, distinguishing it from the 578, 211-2, and 912, which all share a 12W rating.
• All four bulb types in these specifications conform to ANSI standards applicable in both the United States and Canada.
• The bayonet base of the 105 and the wedge base of the 912 represent fundamentally different mounting systems, meaning these two bulb types are not interchangeable even though both operate at 12V.
• The 578 is the most consistently specified map light bulb for the Lincoln Town Car, covering fourteen consecutive model years from 1998 through 2011.