Peterbilt 359 Headlight Bulb Size

The Peterbilt 359 headlight bulb size specifications include H6054, 9004, and H4651 for high beam applications, along with H6054, 9004, and H4656 for low beam applications. The replacement chart covers vehicle production years from 1986 to 1988 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
1986-1988	H6054 (With 2 Rectangular Headlamps)
	H4651 (With 4 Rectangular Headlamps)
	H5001 (With 4 Round Headlamps)
	9004 (With Halogen Capsule Headlamps)

Low Beam Headlight

Years	Bulb Size
1986-1988	H6054 (With 2 Rectangular Headlamps)
	H4656 (With 4 Rectangular Headlamps)
	H5006 (With 4 Round Headlamps)
	9004 (With Halogen Capsule Headlamps)

Bulb Specifications

Description	Bulb Size
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). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651
ANSI standard (US & Canada). 4-inch square sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5001
ANSI standard (US & Canada). Dual-filament halogen bulb with P29t base. 12V, 65W/45W.	9004
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656
ANSI standard (US & Canada). 5.75-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5006

Other Locations

Additional Notes

The Peterbilt 359 (1986-1988) accommodates four distinct headlamp configurations: two rectangular headlamps, halogen capsule headlamps, four rectangular headlamps, and four round headlamps. Each configuration requires its own specific bulb sizes for both high and low beam functions, and the sizes are not interchangeable across configurations.
The H6054 is a 5x7-inch rectangular sealed beam unit operating at 12V. It serves as both the high beam and low beam bulb in the two-rectangular-headlamp configuration, meaning a single bulb type handles both functions in that setup.
The 9004 is a dual-filament halogen bulb with a P29t base, rated at 12V with 65W for high beam and 45W for low beam. It is the only bulb in these specifications that uses a replaceable capsule rather than a sealed beam unit, and it covers both high and low beam functions within the halogen capsule headlamp configuration.
Sealed beam units, which include the H6054, H4651, H5001, H4656, and H5006, are not serviceable at the bulb level. When a sealed beam fails, the entire unit requires replacement rather than an internal component.
The four-rectangular-headlamp configuration uses two different sealed beam sizes depending on the function: the H4651 (4x6-inch) for high beam and the H4656 (4x6-inch) for low beam. Although both share the same physical format, they are distinct part numbers and are not interchangeable between beam positions.
The four-round-headlamp configuration similarly splits beam functions across two sealed beam units: the H5001 (4-inch square) for high beam and the H5006 (5.75-inch round) for low beam. The physical formats differ between the two positions, making substitution between them impossible.
All bulb types listed across these specifications operate at 12V, which is consistent with standard 12-volt electrical systems used in commercial vehicle applications of this period.
All six bulb types conform to ANSI standards recognized in both the United States and Canada, placing them within a regulated sizing and performance framework applicable across North American markets.