White WIM Headlight Bulb Size

The White WIM headlight bulb size chart specifies high beam and low beam bulb options including 9004, H6024, H4651, and H4656 sizes for this heavy-duty truck model. The replacement chart covers 1984 through 1988 vehicle production years 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

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
1988	9004 (With Composite Headlamps)	HB1	Check Price
1988	H6024 (With Sealed Beam Headlamps)	H6024	Check Price
1984-1987	9004 (Conventional)	HB1	Check Price
1984-1987	H4651 (Except Conventional)	H4651	Check Price

Low Beam Headlight

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
1988	9004 (With Composite Headlamps)	HB1	Check Price
1988	H6024 (With Sealed Beam Headlamps)	H6024	Check Price
1984-1987	9004 (Conventional)	HB1	Check Price
1984-1987	H4656 (Except Conventional)	H4656	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament halogen bulb with P29t base. 12V, 65W/45W.	9004	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.	H4651	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

Other Locations

Additional Notes

The 9004 is a dual-filament halogen bulb rated at 12V with a 65W high beam filament and a 45W low beam filament, fitted with a P29t base. Its dual-filament design allows a single bulb to serve both the high beam and low beam functions within a composite headlamp assembly.
The White WIM uses the 9004 bulb for both high beam and low beam positions in conventional and composite headlamp configurations across the 1984-1988 model years, making it the most frequently specified bulb type in these specifications.
The H6024 is a 7-inch round sealed beam unit operating at 12V. It is not a replaceable bulb in the conventional sense; the entire sealed unit is substituted when replacement is required. It appears on the White WIM (1988) in configurations equipped with sealed beam headlamps.
The H4651 and H4656 are both 4x6-inch rectangular sealed beam units operating at 12V, and both follow the same whole-unit replacement requirement as the H6024. The H4651 is specified for the high beam position, while the H4656 covers the low beam position in non-conventional configurations for the 1984-1987 model years.
Because the H4651 and H4656 share the same physical 4x6-inch rectangular sealed beam format, they are not interchangeable despite their similar appearance. Each unit contains a filament arrangement optimized for its designated beam position, and substituting one for the other would result in incorrect light output.
The 1988 model year represents a transitional point in the specifications, where the headlamp configuration determines the applicable bulb type. Composite headlamp-equipped vehicles use the 9004, while sealed beam-equipped vehicles use the H6024, meaning the two bulb types are mutually exclusive for that year.
All four bulb types listed across these specifications conform to ANSI standards applicable in both the United States and Canada, indicating regulatory compliance across both markets for the applicable model years.