Ford L8501 Headlight Bulb Size

Additional Notes

• The Ford L8501 (1997-1998) supports three distinct headlamp configurations: two round headlamps, composite headlamps, and four rectangular headlamps. Each configuration uses a different bulb type for both high and low beam functions, making correct identification of the headlamp style essential before sourcing a replacement.
• The H6024 is a 7-inch round sealed beam unit operating at 12V and conforming to ANSI standards applicable in both the US and Canada. As a sealed beam design, the entire unit is replaced rather than an internal filament or bulb, and it serves as both the high and low beam source in the two round headlamp configuration on the L8501.
• The 9007 is a dual-filament halogen bulb with a PX29t base, rated at 12V with a wattage of 65W on high beam and 55W on low beam. Its dual-filament construction allows a single bulb to handle both beam functions within composite headlamp housings, distinguishing it from the sealed beam units used in the other configurations.
• The H4651 and H4656 are both 4x6-inch rectangular sealed beam units operating at 12V under ANSI standards. Neither contains a replaceable internal element; the full unit is replaced upon failure. In the four rectangular headlamp configuration, the H4651 is designated for high beam positions and the H4656 for low beam positions.
• Because the H4651 and H4656 share the same physical 4x6-inch rectangular form factor, there is a risk of substituting one for the other. They are not interchangeable, as each is calibrated for a specific beam function, and installing the incorrect unit in a given position would result in improper light output.
• The 9007 bulb with its PX29t base is keyed to prevent incorrect installation orientation, a feature common to asymmetric dual-filament halogen bulbs. This base design ensures the filaments align correctly within the composite reflector housing to produce the intended beam patterns.