GMC K3500 Headlight Bulb Size

The GMC K3500 high beam and low beam headlight bulb sizes include H6054, 9005, H4701 for high beam applications and H6054, 9006, H4703 for low beam applications, with each bulb size representing a distinct specification. The replacement chart covers vehicle production years from 1979 to 2000 and contains corresponding bulb size specifications for each model year.

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
1992-2000	9005 (With Halogen Capsule Headlamps)
1992-2000	H6054 (With Sealed Beam Headlamps)
1988-1991	H6054 (With 2 Rectangular Headlamps)
	H4701 (With 4 Rectangular Headlamps)
	9005 (With Halogen Capsule Headlamps)
1982-1986	H6054 (With 2 Headlamps)
1982-1986	H4651 (With 4 Headlamps)
1981	H6054
1979-1980	H6054 (With 2 Rectangular Headlamps)
1979-1980	H6024 (With 2 Round Headlamps)

Low Beam Headlight

Years	Bulb Size
1992-2000	9006 (With Halogen Capsule Headlamps)
1992-2000	H6054 (With Sealed Beam Headlamps)
1988-1991	H6054 (With 2 Rectangular Headlamps)
	H4703 (With 4 Rectangular Headlamps)
	9006 (With Halogen Capsule Headlamps)
1983-1986	H6054 (With 2 Headlamps)
1983-1986	H4652 (With 4 Headlamps)
1982	H6054 (With 2 Headlamps)
1982	H4656 (With 4 Headlamps)
1981	H6054
1979-1980	H6054 (With 2 Rectangular Headlamps)
1979-1980	H6024 (With 2 Round Headlamps)

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament halogen bulb with P20d base. 12V, 65W.	9005
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, 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). 7-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6024
ANSI standard (US & Canada). Single-filament halogen bulb with P22d base. 12V, 55W.	9006
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 GMC K3500 headlight bulb specifications span the 1979-2000 model years, covering both high beam and low beam positions across multiple headlamp system configurations.
The H6054 is the most frequently listed bulb across the specifications. It is a 5x7-inch rectangular sealed beam unit operating at 12V. As a sealed beam design, the entire unit is replaced rather than an internal filament or capsule, and it carries ANSI standard recognition for the US and Canada markets.
For the GMC K3500 model years 1992-2000 equipped with halogen capsule headlamps, the high beam position uses the 9005 and the low beam position uses the 9006. These are separate, non-interchangeable single-filament halogen bulbs. The 9005 operates at 65W with a P20d base, while the 9006 operates at 55W with a P22d base. The differing base types physically prevent cross-installation between the two positions.
The 1988-1991 four-rectangular-headlamp configuration uses the H4701 for high beam and the H4703 for low beam. Both are 7-inch round sealed beam units operating at 12V, and both require full unit replacement rather than bulb replacement.
The 1983-1986 four-headlamp configurations introduce the H4651 and H4652 for high and low beam positions respectively, both being 4x6-inch rectangular sealed beam units. The 1982 low beam four-headlamp position uses the H4656 instead of the H4652, which is a distinct 4x6-inch rectangular sealed beam unit despite the similar form factor.
The 1979-1980 two-round-headlamp configuration uses the H6024, a 7-inch round sealed beam unit at 12V, for both high and low beam positions. This unit is physically distinct from the H6054 used in the two-rectangular-headlamp configuration of the same years and is not interchangeable with it.
All sealed beam types listed in the specifications, including the H6054, H4701, H4703, H4651, H4652, H4656, and H6024, conform to ANSI standards applicable to the US and Canadian markets and operate at 12V.
The 1991 model year carries the widest range of high beam and low beam options within a single year, with three distinct configurations listed: two-rectangular, four-rectangular, and halogen capsule, each requiring a different bulb type that is not transferable between configurations.