The White WCS front side marker bulb size measures 1157 or 194, while the rear side marker bulb size measures 194. The replacement chart covers vehicle production spanning 1981 to 1988.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The White WCS uses two distinct bulb types across its side marker positions: the 194 and the 1157, both of which conform to ANSI standards recognized in the United States and Canada.
The 194 bulb is a miniature wedge type with a T10 form factor, rated at 12V and 3.78W, making it a low-wattage single-filament lamp suited to marker and clearance lighting applications.
The 1157 bulb is a dual-filament lamp with a BAY15d bayonet base, rated at 12V with filaments drawing 21W and 5W respectively, which allows it to serve both a brighter active state and a dimmer standing-light state from a single housing.
The rear side marker position on the White WCS uses the 194 bulb across all model years from 1981-1988 without variation.
The front side marker position on the White WCS uses the 194 bulb for model years 1981-1987.
The 1988 White WCS front side marker departs from the 194 specification used in prior years, instead requiring the 1157 bulb.
Because the 1157 uses a BAY15d bayonet base and the 194 uses a wedge base, the two bulb types are physically incompatible and not interchangeable with each other.
The wattage difference between the 1157 and the 194 is substantial, with the 1157 high-intensity filament drawing more than five times the wattage of the 194, which reflects a fundamental difference in socket and circuit design between the two positions on the 1988 model.