Nissan 720 high beam headlight bulbs use H4651 size while low beam headlight bulbs use H4656 or H4652 size. The replacement chart contains vehicle production years and bulb size specifications spanning 1980 to 1986.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H4651 is an ANSI-standardized 4x6-inch rectangular sealed beam unit operating at 12V. It is used as the high beam headlight on the Nissan 720 across the full 1980-1986 model range, making it the only high beam fitment listed for this vehicle.
Sealed beam units such as the H4651, H4652, and H4656 do not contain a replaceable bulb element. When the unit fails, the entire sealed assembly is replaced rather than an internal filament or capsule.
The H4652, used as the low beam headlight on the 720 from 1980-1985, is classified as a variant of the H4651. Both share the same 4x6-inch rectangular sealed beam format and 12V operating voltage under the ANSI standard.
The 1986 Nissan 720 low beam headlight uses the H4656 rather than the H4652 found in the 1980-1985 model years. Although the H4656 shares the same 4x6-inch rectangular sealed beam format and 12V rating, it is a distinct ANSI type and is not interchangeable with the H4652.
All three sealed beam types listed, the H4651, H4652, and H4656, are standardized under ANSI for use in the United States and Canada. This standardization means physically similar units from different manufacturers conform to the same size and base specifications within each type designation.
The high beam and low beam headlights on the 720 are separate sealed beam units with different ANSI designations. Substituting one type for the other is not supported by the specifications, as each position calls for a distinct unit.