Cadillac Cimarron Headlight Bulb Size

The Cadillac Cimarron high beam headlight uses a 9004 or H4651 bulb size, while low beam headlight applications require a 9004, H4656, or H4652 bulb size. The replacement chart covers 1982 to 1988 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 Size
1986-1988	9004
1982-1985	H4651

Low Beam Headlight

Years	Bulb Size
1986-1988	9004
1984-1985	H4656
1983	H4652
1982	H4656

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament halogen bulb with P29t base. 12V, 65W/45W.	9004
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). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit, variant of H4651. Not a replaceable bulb — the entire unit is replaced. 12V.	H4652

Other Locations

Additional Notes

The 9004 bulb is a dual-filament halogen unit operating at 12V with a power draw of 65W on high beam and 45W on low beam. It uses a P29t base and conforms to ANSI standards applicable in both the United States and Canada.
Because the 9004 handles both high and low beam functions within a single bulb, the Cadillac Cimarron (1986-1988) uses the same 9004 unit across both headlight positions rather than separate bulbs for each function.
The H4651, H4652, and H4656 are all 4x6-inch rectangular sealed beam units operating at 12V under ANSI standards. In sealed beam designs, the lens, reflector, and filament form a single fused assembly, meaning the entire unit is replaced rather than an internal bulb.
On the Cimarron, the H4651 sealed beam served the high beam position across the 1982-1985 model years, while the low beam position used distinct sealed beam variants depending on the year.
The low beam sealed beam specification for the 1983 Cimarron is H4652, which is a variant of the H4651. The 1982, 1984, and 1985 model years used the H4656 in the low beam position instead.
The H4651 and H4656 are separate sealed beam types despite sharing the same 4x6-inch rectangular form factor. Substituting one for the other without confirming the correct specification for a given position and year would be an incorrect fitment.
The transition from sealed beam units to the 9004 halogen bulb occurred between the 1985 and 1986 model years on the Cimarron, reflecting a shift from a fixed-assembly headlight system to one with a replaceable bulb inside a separate housing.
All bulb types listed across both headlight positions on the Cimarron conform to ANSI standards recognized in the United States and Canada, indicating regional standardization rather than global compatibility.