Chevrolet Corsica Automatic Transmission Indicator Bulb Size

The Chevrolet Corsica automatic transmission indicator requires bulb size 73 or 74 depending on the specific application. Data for the bulb sizes covers the range from 1987 to 1996.

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
1995-1996	73
1991-1994	74
1987-1989	74

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 1.4W.	73
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 1.4W.	74

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Additional Notes

The Chevrolet Corsica automatic transmission indicator uses two bulb sizes across its production years: the 73 and the 74. Both are ANSI-standard miniature wedge bulbs of the T5 type, rated at 12 volts and 1.4 watts.
The T5 designation refers to the bulb's tubular envelope width, which is five-eighths of an inch. This is a small-format bulb commonly used in instrument cluster and indicator applications.
Despite sharing the same T5 form factor, voltage, and wattage, the 73 and 74 are distinct part numbers and are not confirmed as interchangeable within these specifications.
The bulb 74 is specified for the Corsica across the 1987-1989 and 1991-1994 model years, making it the more widely used of the two sizes in this application.
The bulb 73 is specified for the 1995-1996 model years, representing a change from the 74 used in earlier production.
Both bulb sizes carry ANSI standardization applicable to the United States and Canada, meaning they conform to a defined set of performance and dimensional criteria recognized across North American markets.
At 1.4 watts and 12 volts, both bulbs draw very low current, which is consistent with their role as indicator lamps rather than primary illumination sources.