BMW 735i License Plate Bulb Size

The BMW 735i license plate light requires a DE3423 bulb size for proper illumination of the rear registration area. Data for the specified component covers the range from 1985 to 1992.

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
1985-1992	DE3423

Bulb Specifications

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

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Additional Notes

The DE3423 is the sole license plate bulb size listed for the BMW 735i across all model years in the specifications, spanning 1985-1992.
The DE3423 is classified as a festoon bulb, a cylindrical lamp type that seats between two spring-loaded end-cap contacts rather than using a traditional socket base.
Festoon bulbs are held in place by tension from the end-cap contacts, meaning the physical length of the bulb is a critical fitment factor.
The DE3423 has a 41mm length, which determines its compatibility with the license plate lamp housing on the BMW 735i.
The bulb operates at 12 volts, consistent with the standard electrical system voltage found in passenger vehicles of this era.
The DE3423 carries an ANSI designation, indicating it conforms to a standardized specification recognized in both the United States and Canada.
Because festoon bulbs of different lengths share similar end-cap contact designs, substituting a bulb of a different length risks poor contact, intermittent illumination, or failure to seat securely in the housing.