The Chevrolet C50 front turn signal bulb size measures 1157 or 2057, while the rear turn signal bulb size measures 1157. The replacement chart covers vehicle production years spanning 1960 to 1988.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1157 is the dominant turn signal bulb type across the Chevrolet C50 specifications, appearing in both the front and rear turn signal positions for the majority of the model years covered.
The 1157 is a dual-filament bulb operating at 12 volts with a BAY15d bayonet base, rated at 21W on the high filament and 5W on the low filament, conforming to ANSI standards recognized in both the United States and Canada.
The BAY15d bayonet base features two offset pins, a design that physically prevents single-filament bulbs from being seated in sockets intended for dual-filament applications.
The Chevrolet C50 front turn signal uses the 2057 bulb for the 1983-1984 model years, while all other years in the front position use the 1157.
The 2057 shares the same BAY15d bayonet base as the 1157 and operates at 12 volts, but draws 26.9W on the high filament and 8W on the low filament, making it a higher-wattage variant of the same base type.
Because the 2057 draws more current than the 1157, substituting one for the other in years where a specific type is specified may affect the behavior of load-sensitive turn signal flasher units.
The rear turn signal position uses the 1157 uniformly across all model years from 1960-1988, with no variation recorded in the specifications.
The front and rear turn signal positions share the same bulb type for all years except 1983-1984, when the front position specifies the 2057 while the rear continues to use the 1157.