Chevrolet K5 Blazer Headlight Bulb Size

The Chevrolet K5 Blazer headlight bulb specifications include high beam sizes H6054, H4651, and H6024, along with low beam sizes H6054, H4656, and H4652 in various bulb configurations. The replacement chart covers 1975 through 1986 production years with corresponding size data.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

High Beam Headlight

Years	Bulb Type	Shop
1982-1986	H6054 (With 2 Headlamps)	Check Price
1982-1986	H4651 (With 4 Headlamps)	Check Price
1981	H4651	Check Price
1980	H6024	Check Price
1979	H6054 (With 2 Rectangular Headlamps)	Check Price
1979	H6024 (With 2 Round Headlamps)	Check Price
1975-1978	H6024	Check Price

Low Beam Headlight

Years	Bulb Type	Shop
1985-1986	H6054 (With 2 Headlamps)	Check Price
1985-1986	H4656 (With 4 Headlamps)	Check Price
1982-1984	H6054 (With 2 Headlamps)	Check Price
1982-1984	H4652 (With 4 Headlamps)	Check Price
1981	H4652	Check Price
1980	H6024	Check Price
1979	H6054 (With 2 Rectangular Headlamps)	Check Price
1979	H6024 (With 2 Round Headlamps)	Check Price
1975-1978	H6024	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). 5x7-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6054	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651	Check Price
ANSI standard (US & Canada). 7-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6024	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit, variant of H4651. Not a replaceable bulb — the entire unit is replaced. 12V.	H4652	Check Price

Other Locations

Additional Notes

The Chevrolet K5 Blazer headlight specifications across 1975-1986 reference sealed beam units exclusively. All bulb types listed, including the H6054, H6024, H4651, H4652, and H4656, are ANSI-standard sealed beam assemblies rated at 12V. In each case, the entire unit is replaced rather than an internal bulb.
The H6054 is a 5x7-inch rectangular sealed beam unit and serves as both the high beam and low beam source on two-headlamp configurations of the Chevrolet K5 Blazer from 1979 and 1982-1986. A single unit type handling both functions is characteristic of a dual-filament sealed beam design.
The H6024 is a 7-inch round sealed beam unit and appears across the 1975-1980 model years, as well as on 1979 configurations equipped with two round headlamps. It is the only round-format sealed beam type referenced in these specifications.
Four-headlamp configurations on the K5 Blazer use separate sealed beam units for high and low beam functions. The high beam position uses the H4651 across 1981-1986, while the low beam position uses either the H4652 (1981-1984) or the H4656 (1985-1986). All three are 4x6-inch rectangular sealed beam units.
The H4652 is described as a variant of the H4651. Although both share the same 4x6-inch rectangular sealed beam format, they are not interchangeable between beam positions, as the H4651 is designated for high beam use and the H4652 for low beam use.
The 1979 model year is the only year in these specifications where both round and rectangular headlamp configurations are listed simultaneously, with the H6024 assigned to two-round-headlamp fitments and the H6054 assigned to two-rectangular-headlamp fitments.
The transition from round to rectangular headlamp formats on the K5 Blazer is reflected in the specifications by the shift from H6024 units to H6054 and H465x-series units. The H6024 does not appear in any configuration after 1980.