BMW 750iL Dome Light Bulb Size

The BMW 750iL dome light requires DE3423 and 6411 bulb sizes for the interior lighting system. Data for the specified components covers the range from 1995 through 2001.

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
1999-2001	DE3423
1995-1998	6411

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423
ANSI standard (US & Canada). Festoon bulb, 36mm length, SV8.5 base. 12V, 5W.	6411

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Additional Notes

The BMW 750iL dome light specifications cover model years 1995-2001 and reference two bulb sizes: DE3423 and 6411.
Both the DE3423 and 6411 are festoon-type bulbs, meaning they are cylindrical lamps that mount between two end contacts rather than fitting into a socket with a traditional base.
The DE3423 is specified for the 1999-2001 BMW 750iL. It follows the ANSI standard applicable to the US and Canadian markets and has a 41mm length with end-cap contacts operating at 12V.
The 6411 is specified for the 1995-1998 750iL. It also conforms to the ANSI standard for US and Canadian markets and carries a 36mm length with an SV8.5 base, rated at 12V and 5W.
The DE3423 and 6411 differ in length by 5mm, with the DE3423 being the longer of the two. This physical difference means the two bulbs are not directly interchangeable despite both being festoon types.
The SV8.5 base designation on the 6411 refers to a festoon base with an 8.5mm cap width, a common standard in European automotive lighting applications.
No wattage rating is listed in the specifications for the DE3423, whereas the 6411 is rated at 5W. Both operate on a 12V electrical system, consistent with standard automotive voltage.
A fitment change occurred between the 1998 and 1999 model years, when the dome light bulb specification shifted from the 6411 to the DE3423. Installing the incorrect size for a given model year risks poor contact or fitment failure within the dome light housing.