The Ford L8000 high beam headlight uses H6024 or H4651 bulb size, while low beam headlight uses H6024 or H4656 bulb size. The replacement chart covers 1981 to 1988 vehicle production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Ford L8000 (1981-1988) uses two distinct headlamp configurations: a two-lamp system with round housings and a four-lamp system with rectangular housings. The correct bulb type is determined entirely by which configuration is present on the vehicle.
The H6024 is a 7-inch round sealed beam unit operating at 12V and conforming to ANSI standards applicable in both the United States and Canada. It serves as both the high beam and low beam in the two-round-lamp configuration, meaning a single bulb type covers both functions in that system.
Because the H6024 is a sealed beam unit rather than a replaceable bulb, the entire assembly is replaced as one piece when the unit fails or is damaged.
The four-rectangular-lamp configuration splits high and low beam functions between two different bulb types. The H4651 handles high beam duties, while the H4656 handles low beam duties across all model years covered in the specifications.
The H4651 and H4656 are both 4x6-inch rectangular sealed beam units rated at 12V and built to the same ANSI standard. Despite sharing the same physical form factor, they are not interchangeable, as each is optically designed for its specific beam function.
All three bulb types, H6024, H4651, and H4656, are sealed beam units. In each case, the lens, reflector, and filament form a single non-serviceable assembly, and the whole unit is replaced rather than an internal component.
The bulb specifications for the Ford L8000 remain unchanged across the full 1981-1988 model year range, with no variation in bulb type for either headlamp configuration during that period.
All bulb types listed in the specifications operate at 12V, which is consistent with standard 12-volt automotive electrical systems used in commercial vehicles of this type.