BMW 740i Dome Light Bulb Size

The BMW 740i dome light requires bulb sizes 12961, DE3423, and 6411 depending on the specific application for the vehicle. Data for the bulb sizes covers the range from 1995 through 2015.

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
2011-2015	12961
1999-2001	DE3423
1997-1998	6411
1995	6411

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
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

Other Locations

Additional Notes

The BMW 740i dome light specifications reference three distinct bulb types across the model's history: the 12961, DE3423, and 6411.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, fitted with a W2.1x9.5d base and rated at 12V, 5W. It is the bulb type specified for the 2011-2015 BMW 740i dome light.
The T10 wedge base on the 12961 is a push-in style connector, meaning the bulb seats directly into a socket without a separate locking mechanism.
The DE3423 follows the ANSI standard recognized in the United States and Canada. It is a festoon-style bulb with a 41mm length and end-cap contacts, rated at 12V, and is specified for the 1999-2001 740i.
The 6411 is also an ANSI-standard festoon bulb, rated at 12V and 5W, but with a 36mm length and an SV8.5 base. It is specified for the 1995-1998 740i dome light.
Although both the DE3423 and 6411 are festoon-type bulbs sharing the same 12V rating, their differing lengths (41mm versus 36mm) and base types make them non-interchangeable with each other.
The SV8.5 base on the 6411 refers to a festoon bulb with a specific cap width of 8.5mm, a detail that distinguishes it physically from the end-cap contact style used on the DE3423.
The 12961 wedge bulb and the two festoon types (DE3423 and 6411) use fundamentally different socket designs, so none of the three bulb types are cross-compatible with one another.