Chevrolet Cavalier Trunk Bulb Size

The Chevrolet Cavalier trunk light uses bulb sizes 105, 561, 912, and 1003 depending on the specific version of the vehicle. Available data for the lighting components covers the range from 1982 through 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
2000-2005	912
1994	561
1993	105
1991-1992	912
1985-1990	1003
1983-1984	561
1982	1003

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	105
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1003

Other Locations

Additional Notes

The Chevrolet Cavalier trunk bulb specifications span model years 1982 through 2005, with four distinct bulb types used across that period: the 912, 561, 105, and 1003.
The 912 is the most frequently specified trunk bulb across the Cavalier lineup, appearing in the 1991-1992 and 2000-2005 model years. It is a T15 wedge bulb rated at 12V and 12W, conforming to ANSI standards for the US and Canadian markets.
The 912 is a variant of the 921 bulb. While the two share a wedge base form factor, they are not identical, and substitution between them warrants attention to wattage and fitment tolerances.
The 1003 bulb is the second most common type in these specifications, covering the 1982 and 1985-1990 model years. It uses a BA15s bayonet base and is rated at 12V and 21W, making it the highest-wattage trunk bulb among those listed.
The 561 is a festoon-type bulb with a 44mm length and end-cap contacts, rated at 12V and 12W. It is specified for the 1983-1984 and 1994 Cavalier model years.
Festoon bulbs such as the 561 are physically distinct from both wedge and bayonet-base types, as they are held in place by spring clips at each end rather than inserted into a socket, making them non-interchangeable with the other bulb types in these specifications.
The 105 bulb is specified exclusively for the 1993 Cavalier. It uses a BA15s bayonet base and is rated at 12V and 13W. It is described as a variant of the 1156, though it differs in wattage from the standard 1156 rating.
Both the 105 and the 1003 share a BA15s bayonet base, but their wattage ratings differ at 13W and 21W respectively. This electrical difference makes them non-interchangeable despite the shared base type.
The 1994 model year returns to the 561 festoon bulb after the 1993 model year used the 105 bayonet-base type, and the 2000-2005 years use the 912 wedge type, reflecting that no single bulb type was used continuously across all years.
All four bulb types in these specifications conform to ANSI standards applicable in both the United States and Canada, indicating a shared regulatory framework for their electrical and physical ratings.