Ram ProMaster City License Plate Bulb Size

Additional Notes

• The Ram ProMaster City uses the DE3423 bulb for its license plate lighting across the 2015-2021 model years covered in these specifications.
• 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 screw or bayonet base.
• The DE3423 operates at 12 volts, which is consistent with standard automotive electrical systems.
• The DE3423 has a length of 41mm, a figure that is critical for fitment, as festoon bulbs must physically span the contact points of their housing to make a proper electrical connection.
• The DE3423 carries ANSI standardization applicable in both the United States and Canada, meaning the bulb conforms to a defined set of performance and construction criteria recognized across North America.
• Because the DE3423 is an ANSI-standardized festoon type, aftermarket and OEM replacements labeled DE3423 from different manufacturers are generally interchangeable, provided the 41mm length and end-cap contact design are maintained.
• Festoon bulbs of similar length but different contact styles, such as dome-type or pin-base variants, are not compatible with the DE3423 socket even if the overall length is close, as the contact mechanism differs.