Chevrolet K5 Blazer Courtesy Bulb Size

Chevrolet K5 Blazer courtesy bulb sizes include 1003, 1004, and 1156 bulb options across different model configurations. The replacement chart covers vehicle production years from 1975 to 1986 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

YearsBulb Size
1985-19861003
19841004 (With 2 Headlamps)
19831003 (With 2 Headlamps)
19801156
19791003
1975-1978105

Bulb Specifications

Description Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.1003
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.1004
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. Variant of 1156. 12V, 13W.105

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