BMW 328i Map Light Bulb Size

The BMW 328i map light requires bulb sizes DE3423 and 6411 for the interior lighting system. Data for the specified components covers the period from 1996 through 2000.

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
2000	DE3423
1997-1999	DE3423 (Rear)
1996	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 328i map light specifications reference two festoon bulb types across the 1996-2000 model years: the DE3423 and the 6411.
Festoon bulbs are cylindrical lamps that mount horizontally between two spring-loaded end contacts or a base socket, a form factor common in interior dome and map lighting applications.
The DE3423 is an ANSI-standard festoon bulb rated at 12V with a 41mm length and end-cap contacts, meaning the electrical connection is made at both ends of the bulb rather than through a dedicated base.
The 6411 is an ANSI-standard festoon bulb rated at 12V and 5W with a 36mm length and an SV8.5 base, a socket-style fitting that differs structurally from the end-cap contact design of the DE3423.
The 5mm difference in length between the DE3423 (41mm) and the 6411 (36mm) means the two bulbs are not physically interchangeable, despite both being festoon types operating on 12V.
The differing base types further reinforce that the DE3423 and 6411 serve distinct socket configurations and cannot substitute for one another.
The 1996 BMW 328i uses the 6411 bulb for its map light, while the 1997-2000 model years reference the DE3423.
The 1997-1999 specifications designate the DE3423 as a rear map light fitment, whereas the 2000 model year lists the DE3423 without a positional qualifier.
Both the DE3423 and the 6411 conform to ANSI standards applicable in the United States and Canada, indicating regional standardization for these part numbers.