Mercedes-Benz ML350 Map Light Bulb Size

Additional Notes

• The Mercedes-Benz ML350 map light specifications cover model years 2003 through 2015, with two distinct bulb types used across that span.
• The 6411 is an ANSI-standard festoon bulb with a 36mm length, SV8.5 base, rated at 12V and 5W. It is the designated map light bulb for the ML350 from 2003 through 2007.
• The 12961 is a Philips part number for a miniature wedge bulb in the T10 form factor, using a W2.1x9.5d base, also rated at 12V and 5W. It is specified for the ML350 from 2008 through 2015.
• Although both bulb types share the same 12V, 5W electrical rating, their physical bases are fundamentally different. The festoon SV8.5 base and the wedge W2.1x9.5d base are not interchangeable, meaning a bulb from one group cannot be fitted into a socket designed for the other.
• The 2012-2015 ML350 specifications designate the 12961 specifically for the rear map light position, indicating the vehicle carries a positional distinction for that bulb in those model years.
• The 2008-2011 ML350 specifications list the 12961 without a positional qualifier, whereas the 2012-2015 entries explicitly label it as a rear fitment.
• The T10 wedge form factor of the 12961 is a widely used miniature bulb standard, and the W2.1x9.5d base designation refers to the wedge-style contact configuration where the bulb body itself forms the electrical connection.
• The SV8.5 base of the 6411 festoon bulb makes contact at both ends of the cylindrical bulb body, a design that requires a holder with two opposing end caps rather than a wedge socket.