Chevrolet Tracker Back Up Light Bulb Size

Chevrolet Tracker back up light bulb specifications include 921 and 1156 sizes for this vehicle model. The replacement chart covers 1998 to 2004 production years with corresponding bulb size data.

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
1999-2004	921
1998	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Chevrolet Tracker uses two distinct back up light bulb types across its model years: the 921 and the 1156, both of which conform to ANSI standards recognized in the United States and Canada.
The 921 bulb is a T15 wedge-type unit, meaning it connects by pressing directly into a wedge socket rather than twisting or locking into place. It operates at 12 volts and draws 16 watts.
The 1156 bulb uses a BA15s bayonet base, a single-contact fitting that locks into its socket with a twist. It also operates at 12 volts but draws 21 watts, making it a higher-wattage unit than the 921.
Because the 921 and 1156 use physically different base types, a wedge socket and a bayonet socket respectively, the two bulbs are not interchangeable without a socket adapter or wiring modification.
The Chevrolet Tracker (1998) takes the 1156 bulb for its back up light, while model years 1999-2004 take the 921 bulb, reflecting a change in socket design between those production periods.
The 5-watt difference between the 1156 at 21 watts and the 921 at 16 watts means the 1998 Tracker back up light produces a modestly higher output from its filament than later model years.
Both the 921 and 1156 are single-filament bulbs, meaning each serves one lighting function only, which is consistent with their application as dedicated back up lights.