Mercedes-Benz 280S License Plate Bulb Size

The Mercedes-Benz 280S uses a DE3423 bulb for the license plate lighting component. Data for the specific bulb requirements spans the period from 1968 through 1976.

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
1975-1976	DE3423
1968-1971	DE3423

Bulb Specifications

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

Other Locations

Additional Notes

The DE3423 is a festoon-type bulb, meaning it is cylindrical in shape and makes electrical contact through metal caps at each end rather than through a base socket or pins.
The Mercedes-Benz 280S uses the DE3423 bulb for its license plate lighting across all listed model years.
The listed years span 1968-1971 and 1975-1976, representing the full range of model years covered by these specifications.
The DE3423 operates at 12 volts, consistent with the standard 12-volt electrical systems found in passenger vehicles of this era.
The DE3423 is classified under the ANSI standard, indicating it conforms to the American National Standards Institute's bulb coding system used across the United States and Canada.
At 41mm in length, the DE3423 must fit within a festoon holder of that specific span, as festoon bulbs are sized by the distance between their two end contacts.
The end-cap contact design of the DE3423 means the bulb is held under spring tension between two contact points inside the lamp housing, a common fitment method for license plate lamp assemblies of this period.
Substituting a festoon bulb of a different length, such as the similar-looking 36mm or 44mm variants, would result in an improper fit due to the fixed spacing of the end-cap contacts in the housing.