Buick Skyhawk Headlight Bulb Size

The Buick Skyhawk headlight bulb specifications include high beam sizes H4701, H4651, and H6054, along with low beam sizes H4703, H4652, and H4656 in various bulb configurations. The replacement chart covers vehicle production years from 1975 to 1989 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.

High Beam Headlight

Years	Bulb Size
1989	H4701
1982-1988	H4651
1979-1980	H6054
1975-1978	H4651

Low Beam Headlight

Years	Bulb Size
1989	H4703
1986-1988	H4652
1985	H4656
1983-1984	H4652
1982	H4656
1979-1980	H6054
1978	H4652
1976-1977	H4656
1975	H4652

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). 7-inch round sealed beam unit, variant. Not a replaceable bulb — the entire unit is replaced. 12V.	H4701
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651
ANSI standard (US & Canada). 5x7-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6054
ANSI standard (US & Canada). 7-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4703
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit, variant of H4651. Not a replaceable bulb — the entire unit is replaced. 12V.	H4652
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656

Other Locations

Additional Notes

The Buick Skyhawk headlight specifications span the 1975-1989 model years, covering both high beam and low beam positions across all listed years.
All bulb types used in the Skyhawk are sealed beam units operating at 12V and conforming to ANSI standards recognized in the United States and Canada. Because they are sealed beam units, the entire housing assembly is replaced rather than an internal filament or capsule.
The H4651 is the most frequently specified high beam bulb across the Skyhawk lineup, appearing in the 1975-1978 and 1982-1988 model years. It is a 4x6-inch rectangular sealed beam unit.
The H4652, a variant of the H4651 sharing the same 4x6-inch rectangular sealed beam format, is the most commonly specified low beam bulb, covering the 1975, 1978, 1983-1984, and 1986-1988 model years.
The 1979-1980 Buick Skyhawk uses the H6054 for both the high beam and low beam positions. The H6054 is a 5x7-inch rectangular sealed beam unit, making it physically distinct from the 4x6-inch units used in most other model years.
The 1989 model year stands apart from all others in the Skyhawk range by specifying round sealed beam units: the H4701 for high beam and the H4703 for low beam. Both are 7-inch round units, with the H4701 noted as a variant of the H4703.
The H4656, a 4x6-inch rectangular sealed beam unit, appears as the low beam specification for the 1976-1977, 1982, and 1985 model years. Although it shares the same physical format as the H4651 and H4652, it carries a distinct ANSI designation and is not listed as a variant of either.
Because the H4652 is designated a variant of the H4651, the two share a physical format, though their differing ANSI codes indicate they are not interchangeable without confirming beam pattern and photometric compliance for the specific application.