Pontiac Bonneville Headlight Bulb Size

Additional Notes

• The Pontiac Bonneville uses the 9005 bulb for high beam and the 9006 for low beam across the 1987-2003 model years. Both are single-filament halogen bulbs operating at 12V, with the 9005 rated at 65W using a P20d base and the 9006 rated at 55W using a P22d base. These two types are not interchangeable despite their physical similarity, as the base configurations differ.
• Sealed beam units appear throughout the earlier model years of the Bonneville. Unlike the halogen bulbs used from 1987 onward, sealed beam units are self-contained assemblies in which the lens, reflector, and filament form a single unit. When the filament fails, the entire assembly requires replacement rather than just the bulb.
• The 1958-1973 Bonneville uses H5001 for high beam and H5006 for low beam. The H5001 is a 4-inch square sealed beam unit, while the H5006 is a 5.75-inch round sealed beam unit. These two types serve distinct beam functions and are not interchangeable with each other.
• The 1957 Bonneville uses the H6024 for both high beam and low beam positions. The H6024 is a 7-inch round sealed beam unit operating at 12V, making it the only type in these specifications shared across both beam positions for a given year.
• The H4651 and H4656 are both 4x6-inch rectangular sealed beam units, with H4651 designated for high beam use and H4656 for low beam use. Although they share the same physical format, they are separate ANSI-designated types and are not rated as interchangeable between beam positions.
• The H4652 is described as a variant of the H4651 and also takes the form of a 4x6-inch rectangular sealed beam unit. It appears in the low beam position for the 1979-1980 and 1984-1985 model years, while other years in the same general period use the H4656 in that position instead.
• The 1982 Bonneville uses the H6054 for both high beam and low beam. The H6054 is a 5x7-inch rectangular sealed beam unit, making it physically larger than the 4x6-inch H4651 and H4656 units used in surrounding years. This makes the 1982 fitment distinct from adjacent model years.
• All sealed beam types listed in these specifications, including the H4651, H4652, H4656, H5001, H5006, H6024, and H6054, conform to ANSI standards applicable in the United States and Canada and operate at 12V. Their standardized sizing means physical form factor compatibility may exist across different makes and models, but beam function designations still govern correct fitment.