BMW 320i License Plate Bulb Size

The BMW 320i license plate light requires a DE3423 bulb size for the rear exterior illumination system. Available data for the specified vehicle covers the period from 1977 through 1983.

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
1977-1983	DE3423

Bulb Specifications

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

Other Locations

Additional Notes

The BMW 320i uses the DE3423 bulb size for the license plate position across the 1977-1983 model years.
The DE3423 is a festoon-type bulb, which means it is cylindrical in shape and makes electrical contact through metal caps at both ends rather than through a base socket.
The DE3423 operates at 12 volts, consistent with the standard electrical system voltage found in passenger vehicles of this era.
The DE3423 has a 41mm length, which is the critical fitment factor for festoon bulbs, as the housing span between the two contact points must match this figure for proper installation.
The DE3423 carries ANSI standardization, meaning its specifications are governed by a recognized North American standards body and the bulb is rated for use in both the United States and Canada.
Because the DE3423 uses end-cap contacts, substituting a festoon bulb of a different length would result in either a loose fit or an inability to seat within the license plate lamp housing of the BMW 320i.