Cadillac Series 60 Fleetwood Turn Signal Bulb Size
Cadillac Series 60 Fleetwood front and rear turn signal bulbs utilize 1157, 1034, or 1154 size specifications depending on production year. The replacement chart covers 1950 through 1964 model years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1034 bulb is the most frequently specified type across the Cadillac Series 60 Fleetwood turn signal data, covering both front and rear positions for the 1953-1963 model years.
The 1034 is a dual-filament bulb rated at 12V and 21/5W, mounted on a BAY15d bayonet base, and is classified as a variant of the 1157 under the ANSI standard applicable in the US and Canada.
The 1157 bulb shares the same BAY15d bayonet base and 12V, 21W/5W dual-filament configuration as the 1034, making the two types closely related in electrical and physical design.
The 1964 Cadillac Series 60 Fleetwood uses the 1157 in both the front and rear turn signal positions, marking a change from the 1034 used in the preceding model years.
The 1154 is an older dual-filament variant of the 1157 rated for 6V/12V operation, also on a BAY15d bayonet base, and was specified for the 1950-1952 model years in both front and rear positions.
The dual-voltage rating of the 1154 (6V/12V) reflects the transitional period in automotive electrical systems when 6-volt platforms were still in use alongside emerging 12-volt designs.
All three bulb types in these specifications share the BAY15d bayonet base, a two-pin offset base that physically prevents single-filament substitutions and ensures correct polarity alignment.
Although the 1034, 1154, and 1157 share the same base type, their differing voltage ratings and ANSI classifications indicate they are not unconditionally interchangeable across all model years.
The front and rear turn signal bulb specifications are identical for every model year listed, meaning no distinction was made between front and rear socket requirements on the Series 60 Fleetwood across the 1950-1964 range.
The shift from the 1154 to the 1034 between the 1952 and 1953 model years corresponds to the broader industry transition from 6-volt to standardized 12-volt automotive electrical systems.