Chevrolet Avalanche Trunk Bulb Size

The Chevrolet Avalanche trunk utilizes a 921 bulb size for the specific lighting component located within the rear storage area. Data for the specified vehicle covers the period from 2007 through 2013.

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
2007-2013	921 (Open Trunk)

Bulb Specifications

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

Other Locations

Additional Notes

The Chevrolet Avalanche uses the 921 bulb for the open trunk position across the 2007-2013 model years.
The 921 is an ANSI-standardized bulb type recognized in both the United States and Canada, operating at 12 volts and 16 watts.
The 921 follows a T15 wedge base configuration, meaning it is retained by friction rather than a twist-lock or bayonet mechanism.
The T15 designation refers to the bulb's tubular glass envelope, with the numeric portion indicating a width of 15/8 of an inch.
Wedge-base bulbs such as the 921 are not interchangeable with bayonet-style or screw-base bulbs, as the socket type is physically incompatible.