Chevrolet Truck front and rear turn signal bulb sizes include 1156, 1073, and 1154 options for the specified bulb applications. The replacement chart covers vehicle production years from 1950 to 1960 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1154 bulb is the most frequently specified type across the Chevrolet Truck turn signal application, covering both front and rear positions for the 1950-1955 model years.
The 1154 is a dual-filament bulb operating on a BAY15d bayonet base, rated for both 6V and 12V systems, and is noted as an older variant of the widely known 1157 bulb.
The 1156 bulb is specified for both front and rear turn signals on the 1958-1960 Chevrolet Truck, making it the most recent bulb type listed across these specifications.
The 1156 is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W under the ANSI standard applicable to the US and Canada.
The 1073 bulb shares the same BA15s bayonet base as the 1156 but operates at a lower wattage of 13W, and it is explicitly described as a lower wattage variant of the 1156.
The 1073 is specified for both front and rear positions on the 1956-1957 model years, serving as a transitional bulb type between the earlier 1154 and the later 1156 in this application.
All three bulb types across these specifications conform to ANSI standards recognized in both the US and Canada.
The BAY15d base of the 1154 features offset pins, which physically prevents it from being interchanged with bulbs using the BA15s base, such as the 1073 or 1156, despite a superficial resemblance between bayonet-style bases.
Because the 1154 is a dual-filament bulb and the 1156 and 1073 are single-filament types, substitution between these groups would affect circuit function beyond base incompatibility alone.
The front and rear turn signal positions share identical bulb specifications for every model year listed, meaning no asymmetric fitment exists between the two positions within this data set.