Lincoln MKZ Map Light Bulb Size

Additional Notes

• The Lincoln MKZ uses two distinct bulb types across its front and rear map light positions, with the rear position remaining consistent across all model years covered in the specifications.
• The rear map light on the Lincoln MKZ (2007-2012) takes a 578 bulb, a festoon-style lamp with end-cap contacts, a 41mm length, and a 12V, 12W rating.
• Festoon bulbs make contact at both ends of the lamp body rather than through a base socket, which is a defining characteristic shared by both the 578 and 6411 types listed in these specifications.
• The front map light position uses the 12961 bulb for 2008-2012, a miniature wedge-style T10 lamp with a W2.1x9.5d base, rated at 12V and 5W.
• The 12961 is a Philips part number designation rather than an ANSI industry standard number, which distinguishes it from the 578 and 6411 designations used elsewhere in these specifications.
• The 2007 Lincoln MKZ front map light takes a 6411 bulb rather than the 12961 used in later years. The 6411 is a festoon lamp with an SV8.5 base and a 36mm length, rated at 12V and 5W.
• The 6411 and 578 are both festoon-type bulbs, but they are not interchangeable. The 578 is 41mm in length while the 6411 is 36mm, and their base types differ, making physical fitment incompatible between the two positions.
• The front map light socket changed between the 2007 and 2008 model years, shifting from a festoon-type 6411 to a wedge-type 12961. These two bulb formats use fundamentally different mounting and contact systems and are not interchangeable.
• The 578 rear bulb draws 12W, which is notably higher than the 5W rating of both the 12961 and 6411 front bulbs, reflecting a difference in light output demands between the front and rear map light positions.
• The W2.1x9.5d base on the 12961 bulb refers to a wedge-type base with a 2.1mm wire width and a 9.5mm insertion depth, a standardized format common to T10 miniature bulbs used in low-current interior lighting applications.