BMW 323i Map Light Bulb Size

The BMW 323i map light requires bulb size 12961 or DE3423 depending on the specific application. Data for the bulb sizes covers the range from 1999 to 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	12961
1999	DE3423

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

Other Locations

Additional Notes

The 2000 BMW 323i map light uses the 12961 bulb, a Philips part number designation for a T10 miniature wedge type with a W2.1x9.5d base, rated at 12 volts and 5 watts.
The T10 wedge bulb format referenced by the 12961 uses a plastic wedge base that makes direct contact with the socket without a separate metal cap or pins, which is a common trait of low-wattage interior lighting applications.
The 1999 BMW 323i map light uses the DE3423, an ANSI-designated festoon bulb with a 41mm length and end-cap contacts, rated at 12 volts.
Festoon bulbs such as the DE3423 make electrical contact through metal caps at each end of the cylindrical glass tube, a design that differs fundamentally from the wedge base of the 12961.
The two model years use physically incompatible bulb types. The 1999 specification calls for a festoon format while the 2000 specification calls for a wedge format, meaning the bulbs are not interchangeable between these years.
The DE3423 follows ANSI standardization, which applies across the United States and Canada, indicating the bulb is sourced according to North American trade specifications rather than a manufacturer-specific part number.
The 12961 carries a manufacturer-specific designation from Philips rather than an ANSI or trade standard code, which is a distinction relevant when sourcing equivalent replacement parts from other suppliers.