The Jeep J20 headlight bulb uses H6054 and H6024 sizes for both high and low beam applications. The replacement chart covers 1974 to 1988 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 Jeep J20 uses two distinct sealed beam headlight units across its model years: the H6054, a 5x7-inch rectangular unit, and the H6024, a 7-inch round unit. Both conform to ANSI standards recognized in the United States and Canada and operate on 12 volts.
Sealed beam units are self-contained assemblies in which the filament, reflector, and lens are fused into a single housing. When a sealed beam fails, the entire unit is replaced rather than an internal bulb.
The H6054 rectangular sealed beam applies to the Jeep J20 for model years 1979-1988, covering both the high beam and low beam positions throughout that span.
The H6024 round sealed beam was fitted to the J20 for model years 1974-1978, again serving both the high beam and low beam positions.
The H6054 and H6024 are not interchangeable. The rectangular and round form factors are physically incompatible with each other's mounting housings, making cross-substitution between the two unit types impossible without modification to the vehicle.
Both the H6054 and H6024 follow ANSI standardization, meaning units from different manufacturers that carry the same designation share identical optical and physical specifications, allowing substitution between brands within the same type.
The J20 underwent a headlight unit change between the 1978 and 1979 model years, shifting from the round H6024 format to the rectangular H6054 format across both beam positions simultaneously.