Chevrolet Biscayne Engine Compartment Light Bulb Size

Chevrolet Biscayne engine compartment light bulb sizes include 1003, 1156, and 93 configurations across different model generations. The replacement chart covers 1958 through 1972 production years with corresponding bulb size specifications.

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	1003
1970	1156
1968-1969	93
1964-1967	1156
1958-1963	94

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
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	94

Other Locations

Additional Notes

The 1156 bulb is the most frequently specified type across the Chevrolet Biscayne engine compartment light fitment data, covering model years 1964-1967 and 1970.
The 94 bulb is the second most recurring type, specified for the Biscayne across model years 1958-1963.
The 1156 is an ANSI-standard single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base.
The 94 is an ANSI-standard dual-filament bulb rated at 12V with a 21/5W output, fitted with a BAY15d bayonet base, which is a two-pin offset base designed to prevent incorrect installation.
The BAY15d base of the 94 is physically distinct from the BA15s base used by the 1156, 1003, and 93, making these bulb types non-interchangeable despite their similar appearance.
The 93 bulb shares the BA15s bayonet base with the 1156 but operates at a lower wattage of 13W versus 21W, classifying it as a reduced-output variant of the 1156 type.
The 1003 bulb, specified for the 1972 Biscayne, shares the same BA15s base, 12V rating, and 21W output as the 1156, making the two electrically equivalent under ANSI standards.
Because the 1003 and 1156 share identical base type and electrical ratings, the distinction between them is one of ANSI designation rather than physical or functional difference in this application.
The 93 bulb, specified for the Chevrolet Biscayne in 1968-1969, draws less current than the 1156 due to its lower wattage, which affects brightness output in the engine compartment.
All four bulb types in these specifications conform to ANSI standards recognized in both the United States and Canada.