Mercury Cougar Headlight Bulb Size

Additional Notes

• The Mercury Cougar's headlight specifications span the 9005, 9006, 9007, 9004, H4651, H4652, H4656, H5001, and H5006 bulb types across its model years, all conforming to ANSI standards recognized in the United States and Canada.
• The 9007 is a dual-filament halogen bulb operating at 12V with a 65W high beam filament and a 55W low beam filament, using a PX29t base. The Mercury Cougar (1991-1997) uses this single bulb type for both high and low beam functions, meaning one bulb per headlight housing serves both purposes.
• The 9005 and 9006 are single-filament halogen bulbs, each dedicated to one beam function. The 9005 operates at 65W with a P20d base, while the 9006 operates at 55W with a P22d base. The Cougar uses the 9005 for high beam and the 9006 for low beam across the 1989-1990 and 1999-2002 model years, requiring two separate bulbs per headlight assembly.
• The 9004 is a dual-filament halogen bulb rated at 12V with a 65W high beam filament and a 45W low beam filament, using a P29t base. It serves both beam functions in the 1987-1988 Cougar. Although the 9004 and 9007 are both dual-filament types, their bases and wattage ratings differ, making them non-interchangeable.
• The H4651 and H4652 are both 4x6-inch rectangular sealed beam units operating at 12V. The H4652 is classified as a variant of the H4651. In sealed beam designs, the reflector, lens, and filament are fused into one unit, so the entire assembly is replaced rather than an individual bulb.
• The low beam specifications for the Cougar show that H4652 and H4656 units appear across different years within the 1977-1986 range, both being 4x6-inch rectangular sealed beam formats. These two types are distinct ANSI designations and are not listed as interchangeable within the specifications.
• The H5001 and H5006 are sealed beam units used in the 1967-1976 Cougar. The H5001 is a 4-inch square sealed beam for high beam, while the H5006 is a 5.75-inch round sealed beam for low beam. The physical format difference between these two units reflects a quad-headlight system in which differently shaped housings serve each beam function.
• Across all model years covered, every bulb type listed operates at 12V, consistent with the standard electrical system voltage used in passenger vehicles throughout the period represented.