Mercedes-Benz SL600 Map Light Bulb Size

The Mercedes-Benz SL600 map light utilizes bulb sizes 12961, H6W, and DE3423 depending on the specific version required for the interior illumination. Data for the provided bulb specifications covers the range from 1998 through 2009.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2009	12961
2007-2008	H6W
2004-2006	DE3423
2000-2002	DE3423
1999	12961 (Front and Center)
1998	12961 (Front and Center, From 06/1998)

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ECE standard (Europe & worldwide). Single-filament signalling bulb with BAX9s base. 12V, 6W.	H6W
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423

Other Locations

Additional Notes

The DE3423 is the most frequently specified map light bulb across the Mercedes-Benz SL600 model years covered, appearing in six of the listed years from 2000-2006.
The DE3423 follows the ANSI standard, which is used in the United States and Canada. It is a festoon-type bulb measuring 41mm in length with end-cap contacts and operates at 12V.
The H6W follows the ECE standard, which governs automotive lighting across Europe and much of the world. It is a single-filament signalling bulb fitted with a BAX9s base, rated at 12V and 6W.
The 12961 is a Philips part number designation for a miniature wedge bulb of the T10 type. It uses a W2.1x9.5d base and is rated at 12V and 5W.
The BAX9s base of the H6W is an offset pin base, meaning the two pins are positioned asymmetrically. This design prevents incorrect installation and is not interchangeable with standard BA9s bases.
The Mercedes-Benz SL600 uses the H6W for the 2007-2008 model years, then shifts to the 12961 for 2009, indicating these two bulb types are not interchangeable despite similar wattage ratings, as they use entirely different base configurations.
For the 1999 Mercedes-Benz SL600, the 12961 bulb is specified for both the front and center map light positions, indicating multiple bulb locations within the interior lighting system for that year.
The 1998 model year carries a production date qualifier, with the 12961 specification applying only to vehicles produced from June 1998 onward. Vehicles built before that date may require a different bulb.
The festoon format of the DE3423 relies on contact at both ends of the bulb rather than a keyed or pinned base, which means fitment depends on the physical length of the housing. A festoon bulb of a different length would not make reliable contact in a socket sized for the 41mm DE3423.
The wattage of the DE3423 is not listed in the specifications, whereas both the 12961 and H6W are rated at 5W and 6W respectively, reflecting a 1W difference that may be relevant when substituting one for the other in compatible sockets.