Lincoln Navigator Dome Light Bulb Size

Additional Notes

• The Lincoln Navigator dome light specifications cover model years 1998 through 2018, with three distinct bulb sizes appearing across that span: 12961, 578, and 214-2.
• The 578 is the most frequently specified bulb in these records, appearing across the majority of model years listed.
• The 578 is an ANSI-standard festoon bulb rated at 12V and 12W, with a 41mm length and end-cap contacts that rest against metal terminals at each end of the bulb holder.
• The 214-2 is also an ANSI-standard festoon bulb rated at 12V and 12W with a 41mm length, but it uses an SV8.5 base rather than plain end-cap contacts, which affects physical fitment even though the voltage and wattage are identical to the 578.
• Because the 578 and 214-2 differ in base type, they are not directly interchangeable despite sharing the same length and electrical ratings.
• The Lincoln Navigator (2015-2018) uses the 12961, a miniature wedge bulb of the T10 type with a W2.1x9.5d base, rated at 12V and 5W, which draws significantly less power than the festoon types used in earlier model years.
• The T10 wedge base of the 12961 is a push-in design that locks into a wedge socket, making it physically incompatible with the festoon-style holders used for the 578 and 214-2.
• The 12961 carries a Philips part number rather than an ANSI designation, indicating it is a manufacturer-specific reference rather than a universal industry standard number.
• The 1999 and 2001 model years are specified with the 214-2, while the surrounding years in that era call for the 578, indicating that the base type varied within otherwise similar production periods.