Cadillac DeVille Headlight Bulb Size

Cadillac DeVille high beam headlight bulbs utilize 9005, H4651, or H5001 sizes, while low beam headlight bulbs use 9006, H4652, or H4656 sizes depending on model generation. The replacement chart covers vehicle production years spanning 1953 through 2005 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.

High Beam Headlight

Years	Bulb Size
1987-2005	9005
1975-1986	H4651
1958-1974	H5001
1953-1957	H6024

Low Beam Headlight

Years	Bulb Size
1987-2005	9006
1985-1986	H4652
1984	H4656
1982-1983	H4652
1981	H4656
1977-1980	H4652
1976	H4656
1975	H4652
1958-1974	H5006
1953-1957	H6024

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament halogen bulb with P20d base. 12V, 65W.	9005
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651
ANSI standard (US & Canada). 4-inch square sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5001
ANSI standard (US & Canada). 7-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6024
ANSI standard (US & Canada). Single-filament halogen bulb with P22d base. 12V, 55W.	9006
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit, variant of H4651. Not a replaceable bulb — the entire unit is replaced. 12V.	H4652
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656
ANSI standard (US & Canada). 5.75-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5006

Other Locations

Additional Notes

The Cadillac DeVille uses three distinct bulb types across its high beam and low beam headlight positions: modern halogen bulbs (9005 and 9006) and several sealed beam units (H4651, H4652, H4656, H5001, H5006, and H6024), all conforming to ANSI standards applicable in the United States and Canada.
The 9005 and 9006 are single-filament halogen bulbs operating at 12V. The 9005 draws 65W and uses a P20d base for the high beam position, while the 9006 draws 55W and uses a P22d base for the low beam position. These two bulb types share a similar physical form but have different base configurations, making them non-interchangeable despite their visual resemblance.
The Cadillac DeVille (1987-2005) uses the 9005 for high beam and the 9006 for low beam. These are replaceable halogen bulbs housed within a separate reflector assembly, unlike the sealed beam units used in earlier model years.
Sealed beam units, used across the 1953-1986 model years, are self-contained glass assemblies in which the filament, reflector, and lens are fused into a single unit. When a sealed beam fails, the entire unit requires replacement rather than just the internal bulb.
The H6024 is a 7-inch round sealed beam unit used in both the high beam and low beam positions on the 1953-1957 DeVille. Because both positions share the same bulb type in those years, the H6024 serves a dual-function role within a single headlight system.
The H5001 and H5006 are both 12V sealed beam units used on the 1958-1974 DeVille, with the H5001 serving the high beam and the H5006 the low beam. The H5001 is a 4-inch square unit, while the H5006 is a 5.75-inch round unit, meaning the two are physically distinct and not interchangeable.
The 1975-1986 DeVille uses 4x6-inch rectangular sealed beam units for both headlight positions. The high beam position consistently uses the H4651 across all those years, while the low beam position alternates between the H4652 and H4656 depending on the specific model year, with H4656 specified for 1976, 1981, and 1984.
The H4652 is described as a variant of the H4651, both being 4x6-inch rectangular sealed beam units. Despite their shared physical format, they are designated for different beam positions and are not listed as interchangeable within these specifications.