Plymouth PB150 headlight bulbs utilize H6024 and H4651 sizes for high beam operation and H6024 and H4656 sizes for low beam operation. The replacement chart covers 1981 to 1983 model 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 Plymouth PB150 uses sealed beam headlight units across its 1981-1983 model years, meaning the entire lens-and-filament assembly is replaced as a single unit rather than swapping an internal bulb.
Three sealed beam types appear in these specifications: the H6024, H4651, and H4656, all of which conform to ANSI standards recognized in both the United States and Canada and operate on 12V electrical systems.
The H6024 is a 7-inch round sealed beam unit. It serves as both the high beam and low beam on 1982-1983 PB150 vehicles equipped with the two round headlamp configuration, meaning a single beam type handles both functions across that system.
The H4651 and H4656 are both 4x6-inch rectangular sealed beam units. Despite sharing the same physical format and voltage rating, they are not interchangeable, as the H4651 is designated for high beam duty while the H4656 is designated for low beam duty in the four rectangular headlamp configuration.
The 1981 PB150 is listed exclusively with the four rectangular headlamp configuration, using the H4651 for high beam and the H4656 for low beam, with no round headlamp variant recorded for that year.
For 1982-1983, the PB150 headlamp configuration determines which sealed beam type applies. The two round headlamp setup uses H6024 units for both beams, while the four rectangular headlamp setup uses H4651 for high beam and H4656 for low beam.
Because the H4651 and H4656 share the same 4x6-inch rectangular form factor, substituting one for the other would place an incorrectly aimed beam pattern in the wrong headlamp position, making beam-function verification essential before replacement.