Mercedes-Benz 300SL License Plate Bulb Size

The Mercedes-Benz 300SL license plate light requires a DE3423 bulb size for proper installation and function within the rear exterior lighting assembly. Data for the specified component covers the 1990 to 1993 span of production for the vehicle.

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
1990-1993	DE3423

Bulb Specifications

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

Other Locations

Additional Notes

The Mercedes-Benz 300SL uses the DE3423 bulb for its license plate lighting across the 1990-1993 model years.
The DE3423 is classified as a festoon bulb, a cylindrical form factor that seats between two end-cap contacts rather than using a bayonet or wedge base.
Festoon bulbs are held in place by spring-loaded holders that grip each end of the bulb, making the 41mm length a critical fitment factor.
The DE3423 operates at 12 volts, consistent with the standard electrical systems found in passenger vehicles of this era.
The DE3423 designation follows ANSI standards applicable in both the United States and Canada, indicating the bulb meets regulated performance and dimensional criteria for those markets.
The 41mm length specification is a hard fitment requirement for festoon bulbs, as a shorter or longer bulb will not make proper contact with the spring clips in the housing.
The DE3423 is a direct-fit replacement for all four model years listed, meaning no variation in bulb size exists across the 1990-1993 300SL range for this application.