Volkswagen Quantum high beam and low beam headlight bulbs utilize 9004, H4651, H4656, and H4652 bulb sizes depending on beam type and model configuration. The replacement chart covers 1982 through 1988 vehicle 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 Volkswagen Quantum used two distinct headlight technologies across its production run. The 1982-1986 model years relied on sealed beam units, while the 1987-1988 model years used a 9004 dual-filament halogen bulb with a P29t base rated at 12V and 65W on high beam and 45W on low beam.
The 9004 bulb handles both high and low beam functions within a single unit, made possible by its dual-filament construction. This contrasts with the sealed beam era, where separate unit types were specified for each beam function.
The H4651 sealed beam unit was fitted as the high beam across all 1982-1986 model years. It is a 4x6-inch rectangular sealed beam rated at 12V, and the entire unit is replaced rather than an internal bulb.
The low beam position on the Volkswagen Quantum saw variation within the sealed beam era. The H4656 unit was used in 1983, 1985, and 1986, while the H4652 unit appeared in 1982 and 1984. Both are 4x6-inch rectangular sealed beam units operating at 12V, with H4652 classified as a variant of H4651.
All bulb and sealed beam types listed for the Quantum conform to ANSI standards applicable in the United States and Canada.
Because the H4651, H4652, and H4656 are sealed beam units, fitment involves replacing the entire optical assembly. These types are not interchangeable with the 9004 halogen bulb used in later model years, as the two systems represent fundamentally different headlight constructions.
The H4652 and H4651 share a classification relationship, with H4652 designated as a variant of H4651. Despite this, they occupied different positions in the Quantum's headlight system and were not used interchangeably within the same model year.