Ram 1500 Cargo Box Bulb Size

The Ram 1500 cargo box light requires a 921 bulb size for proper illumination and function. Data for the specific component covers the period from 2021 through 2023.

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
2023	921
2021	921

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

Other Locations

Additional Notes

The 921 bulb is the specified cargo box bulb size for the Ram 1500 across the 2021-2023 model years.
The 921 bulb follows the ANSI standard, which is the recognized specification framework used in the United States and Canada for automotive lighting components.
It is a wedge-type bulb, classified under the T15 form factor. The T15 designation refers to the bulb's tubular shape, with a width of 15 eighths of an inch, and it uses a wedge base rather than a metal screw or bayonet fitting.
The 921 operates at 12 volts and draws 16 watts, which is consistent with standard low-power automotive interior and utility lighting applications.