Chevrolet Caprice Trunk Bulb Size

The Chevrolet Caprice trunk utilizes 6411, 1003, and 89 bulb sizes for illumination within the storage compartment area of the vehicle. Available data covers the range from 1966 through 2017 for the specific lighting components listed in the provided chart.

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
2011-2017	6411
1973-1992	1003
1972	89
1966-1971	1003

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 36mm length, SV8.5 base. 12V, 5W.	6411
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1003
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	89

Other Locations

Additional Notes

The Chevrolet Caprice trunk bulb specifications cover two distinct bulb types across the full model range: the 6411 festoon bulb and the 1003 bayonet bulb, with a single-year exception in 1972 using the 89 bulb.
The 6411 is a festoon-style bulb with an SV8.5 base and a 36mm length, operating at 12V and 5W. Festoon bulbs seat by pressing lengthwise between two spring clips rather than inserting into a socket, which is a physically distinct mounting method from bayonet-base bulbs.
The Chevrolet Caprice (2011-2017) uses the 6411 bulb for trunk illumination across all model years in that range.
The 1003 bulb uses a BA15s single-contact bayonet base, operating at 12V and 21W. The BA15s base type is inserted and locked by a quarter-turn rotation, a fitment method incompatible with the festoon socket used by the 6411.
The 1003 bulb is specified for the Caprice trunk across 1966-1971 and 1973-1992, making it the most widely used trunk bulb type in these specifications by a substantial margin.
The 89 bulb, specified solely for the 1972 Caprice, shares the BA15s bayonet base with the 1003 but operates at 13W rather than 21W. It is described as a lower wattage variant of the 1156 bulb family.
Because the 89 and 1003 bulbs share the same BA15s base, they are physically interchangeable in terms of socket fitment, though their wattage ratings differ. The 6411 festoon bulb is not interchangeable with either bayonet-base type due to its fundamentally different base design.
All three bulb types in these specifications conform to ANSI standards applicable in both the United States and Canada.