Chevrolet Classic Back Up Light Bulb Size

The Chevrolet Classic back up light requires a bulb size of 3057 for the rear lighting assembly. Data for the specified component covers the range from 2004 to 2005.

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
2004-2005	3057

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3057

Other Locations

Additional Notes

The 3057 is an ANSI-standardized bulb used in the United States and Canada, operating at 12 volts with a dual-filament design rated at 27 watts on the high filament and 7 watts on the low filament.
The 3057 follows the T25 wedge form factor, a designation that refers to the bulb's wedge-style base, which connects directly into a socket without requiring a separate metal base or pins.
The Chevrolet Classic (2004-2005) uses the 3057 bulb for the back up light position across both available model years in the specifications.
The dual-filament nature of the 3057 means the bulb serves two distinct brightness levels within a single housing, a characteristic that distinguishes it from single-filament replacements that share the same socket type but are not functionally equivalent.
Substituting a single-filament bulb in place of the 3057 would result in the loss of one of the two filament functions, as the socket is wired to engage both filaments independently.