Chevrolet C70 Courtesy Bulb Size

The Chevrolet C70 courtesy light uses bulb sizes 211-2, 90, and 1003 across various production periods. Available data covers the specific range from 1960 through 1988.

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
1986-1988	211-2
1985	90
1983-1984	1003
1981-1982	90
1979-1980	211-2
1961	90
1960	211-2

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, SV8.5 base. 12V, 12W.	211-2
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 13W.	90
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1003

Other Locations

Additional Notes

The Chevrolet C70 courtesy bulb specifications cover three distinct bulb types across the listed model years: the 211-2, the 90, and the 1003, all of which conform to ANSI standards applicable in the United States and Canada.
The 211-2 is a festoon-style bulb with a 41mm length and an SV8.5 base, rated at 12V and 12W. It is the most frequently specified bulb across the listed years, appearing in 1960, 1979-1980, and 1986-1988.
The 90 is a single-filament bulb with a BA15s bayonet base, rated at 12V and 13W. It is specified for the 1961, 1981-1982, and 1985 model years.
The 1003 is also a single-filament bulb with a BA15s bayonet base, but it is rated at a higher wattage of 21W at 12V. It is specified for the 1983-1984 model years.
Although the 90 and 1003 share the same BA15s bayonet base type, their wattage ratings differ significantly, at 13W and 21W respectively. This difference means the two bulbs are not interchangeable without affecting the electrical load on the circuit.
The 211-2 festoon bulb uses an SV8.5 base, which is physically distinct from the BA15s bayonet base used by both the 90 and the 1003. Festoon bulbs are held in place by spring-loaded end caps rather than a twist-lock or push-in bayonet mechanism, making cross-substitution between these base types mechanically incompatible.