Jaguar XJS License Plate Bulb Size

The Jaguar XJS license plate light requires bulb size DE3423 or 97 depending on the specific version of the vehicle. Available data covers the range from 1976 to 1996.

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
1980-1996	DE3423
1976-1979	97

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	97

Other Locations

Additional Notes

The Jaguar XJS license plate bulb specification splits across two distinct bulb types over the 1976-1996 model range, with the DE3423 festoon bulb covering 1980-1996 and the 97 bayonet bulb covering 1976-1979.
The DE3423 is a festoon-style bulb, meaning it is a cylindrical lamp that makes electrical contact through metal caps at each end rather than through a base socket. Its 41mm length is a critical fitment factor, as festoon bulbs are length-sensitive and an incorrect size will not seat properly in the holder.
The 97 bulb uses a BA15s bayonet base, which is a single-contact bayonet mount. This base type is inserted and locked into the socket with a push-and-twist motion, a fundamentally different mounting method from the end-cap contacts of the DE3423.
Both bulb types operate at 12 volts and conform to ANSI standards applicable in the United States and Canada, indicating they are rated for standard automotive electrical systems.
The 97 bulb carries a 13-watt rating and is classified as a variant of the 1156 bulb family. Despite this family relationship, the 97 and 1156 are not identical and are not interchangeable without confirming socket and wattage compatibility.
The DE3423 and the 97 use entirely different base types, making them physically incompatible with each other's sockets. A 1976-1979 XJS license plate socket is designed for the BA15s bayonet mount and will not accept a festoon bulb, and vice versa for 1980-1996 models.
The DE3423 festoon format is common in European-origin vehicles, which is consistent with the XJS being a British-market model also sold in North America in an ANSI-compliant specification.