White/GMC WHR front side marker bulb uses 1157 size while rear side marker bulb uses 194 size. Replacement chart covers 1989 to 1995 vehicle production years with bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The White/GMC WHR uses the 1157 bulb for the front side marker position across the 1989-1995 model years.
The 1157 is a dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base.
The BAY15d base features two offset pins at different heights, a design that prevents incorrect single-filament bulbs from seating in a dual-filament socket.
The rear side marker position on the WHR uses the 194 bulb across the same 1989-1995 model years.
The 194 is a miniature wedge-style bulb of the T10 form factor, rated at 12V and 3.78W, with no base pins as the wedge itself serves as the electrical contact.
Both the 1157 and 194 are ANSI-standardized bulbs recognized in the United States and Canada, meaning their electrical and physical specifications are governed by a common standard rather than varying by manufacturer.
The front and rear side marker positions on the WHR require different bulb types, and the two are not interchangeable due to differences in wattage, filament count, and base configuration.
The 1157 draws significantly more power than the 194, reflecting the greater light output typically required of a front marker position compared to a rear side marker.