The American Motors Spirit high beam headlight uses an H4651 bulb size, while low beam headlights use H4652 or H4656 bulb sizes. The replacement chart covers 1979 through 1983 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 American Motors Spirit uses the H4651 sealed beam unit for the high beam headlight across all model years from 1979-1983, making it the most consistent fitment in these specifications.
The H4651, H4652, and H4656 are all ANSI-standardized 4x6-inch rectangular sealed beam units operating at 12V. Because they are sealed beam units, the entire housing is replaced as a single assembly rather than an internal bulb being swapped out.
The H4652 is a variant of the H4651 and serves as the low beam counterpart in the Spirit's headlight system for 1979 and 1981-1983. Despite their close relationship, the two part numbers are not interchangeable between high and low beam positions.
The 1980 Spirit (American Motors) is the only model year in these specifications where the low beam headlight uses the H4656 rather than the H4652, making that year's low beam fitment distinct from all other years listed.
The ANSI standardization of the H4651, H4652, and H4656 means these sealed beam units conform to a shared physical and electrical standard recognized across the United States and Canada, which historically allowed for broad cross-brand availability of replacement units.
Because the high beam position uses the H4651 and the low beam position uses either the H4652 or H4656 depending on the year, the two headlight positions on the Spirit require different sealed beam units and are not served by a single common part.