Chevrolet Chevelle Engine Compartment Light Bulb Size

Chevrolet Chevelle engine compartment light bulb sizes include 1003, 1156, and 93 specifications. The replacement chart covers 1964 through 1973 vehicle production years with corresponding bulb size data.

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
1972-1973	1003
1966-1970	1156
1965	93
1964	1156

Bulb Specifications

Description	Bulb Size
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. 12V, 21W.	1156
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	93

Other Locations

Additional Notes

The Chevrolet Chevelle engine compartment light draws from three ANSI-standardized bulb types across its model years: the 1003, 1156, and 93.
All three bulb types share the BA15s bayonet base, a single-contact base design that uses a single pin offset to one side to ensure correct orientation during installation.
The 1003 and 1156 are both rated at 12V and 21W, making them electrically identical despite carrying different ANSI designation numbers.
The 93 bulb is rated at 12V and 13W, placing it at a lower output than the 1003 and 1156 while sharing the same BA15s base type.
Because the 1003 and 1156 share the same base, voltage, and wattage, they are physically and electrically interchangeable in most applications.
The 93 bulb, while physically compatible with the same BA15s socket, draws less current and produces less light than the 1003 and 1156, which affects direct substitution between these types.
The Chevrolet Chevelle used the 1156 bulb for the engine compartment light across 1964-1967 and again in 1970, representing the most frequently specified bulb type in these specifications.
The 1003 bulb was specified for the 1972-1973 model years, while the 93 bulb was specified exclusively for the 1965 model year.