The White/GMC WX headlight bulb uses a 9004 or H6024 size for both high beam and low beam applications. The replacement chart covers vehicle production spanning 1988 to 1995.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The White/GMC WX carries two distinct headlamp system types across the 1988-1995 model years, each requiring a different bulb or unit. Composite headlamp-equipped vehicles use the 9004 bulb, while sealed beam headlamp-equipped vehicles use the H6024 unit.
The 9004 is a dual-filament halogen bulb operating at 12V with a wattage rating 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 through two separate filaments within a single bulb, it serves as the sole headlight bulb in composite headlamp assemblies on the WX, covering both sub-parts listed in the specifications.
The H6024 is a 7-inch round sealed beam unit rated at 12V and also meets ANSI standards for the US and Canadian markets. Unlike the 9004, it is not a replaceable bulb; the entire sealed unit is replaced when the light fails or is damaged.
The H6024 sealed beam unit integrates the lens, reflector, and filament into a single housing. This construction means the optical assembly itself is the serviceable component, rather than an internal bulb within a separate housing.
The two headlamp types on the WX are not interchangeable. Composite and sealed beam assemblies use different mounting configurations and electrical connections, so the bulb or unit specified for one system is not compatible with the other.
The 9004 bulb features an asymmetric wattage split between its two filaments, with the high beam filament drawing significantly more power than the low beam filament. This difference in wattage produces a higher light output for high beam operation.
Both the 9004 and H6024 specifications remain consistent across all eight model years covered, indicating no change in headlamp bulb requirements for the WX throughout the 1988-1995 period.