Mercury Colony Park Headlight Bulb Size

Mercury Colony Park high beam and low beam headlight bulbs utilize H4651, H5001, H4656, H4652, and H5006 sizes depending on generation. The replacement chart covers 1957 through 1991 production years with corresponding bulb specifications.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

High Beam Headlight

Years	Bulb Type	Shop
1987-1991	H4651	Check Price
1957-1974	H5001	Check Price

Low Beam Headlight

Years	Bulb Type	Shop
1991	H4656	Check Price
1990	H4652	Check Price
1989	H4656	Check Price
1988	H4652	Check Price
1987	H4656	Check Price
1957-1974	H5006	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651	Check Price
ANSI standard (US & Canada). 4-inch square sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5001	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit, variant of H4651. Not a replaceable bulb — the entire unit is replaced. 12V.	H4652	Check Price
ANSI standard (US & Canada). 5.75-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5006	Check Price

Other Locations

Additional Notes

The Mercury Colony Park uses two distinct sealed beam form factors across its production span: a 4-inch square unit (H5001/H5006) for the 1957-1974 model years and a 4x6-inch rectangular unit (H4651/H4652/H4656) for the 1987-1991 model years. These two form factors are physically incompatible with one another.
All five bulb types specified for the Colony Park, H4651, H4652, H4656, H5001, and H5006, conform to ANSI standards recognized in both the United States and Canada. Each operates at 12 volts.
Every headlight unit specified is a sealed beam assembly, meaning the lens, reflector, and filament are fused into a single unit. Replacement requires substituting the entire assembly rather than an internal bulb.
The H5001 serves as the high beam unit and the H5006 as the low beam unit for the 1957-1974 model years. The H5006 is a 5.75-inch round sealed beam, while the H5001 is a 4-inch square sealed beam, making the two non-interchangeable despite sharing the same production era.
For the 1987-1991 model years, the high beam position uses the H4651 across all five years without variation. The low beam position, however, alternates between the H4656 (1987, 1989, 1991) and the H4652 (1988, 1990), indicating that year-specific fitment must be confirmed before replacement.
The H4652 is classified as a variant of the H4651. Both are 4x6-inch rectangular sealed beam units, but they are designated separately, and substituting one for the other without confirming compatibility with the specific model year is not supported by the specifications.