Cadillac Calais front and rear turn signal bulbs utilize 1034NA and 1157NA bulb sizes for the front position, while rear turn signals employ 1157, 1034NA, and 1157NA bulb sizes. The replacement chart covers 1965 through 1976 production years 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 1034NA, 1157NA, and 1157 bulbs all share the BAY15d bayonet base, meaning the physical mounting interface is identical across all three types used in the Cadillac Calais turn signal positions.
All three bulb types operate at 12 volts with a dual-filament configuration rated at 21W and 5W, where the higher wattage filament serves the turn signal function and the lower wattage filament serves a secondary purpose such as parking or running light duty.
The 1034NA is described as a variant of the 1157, and both the 1034NA and 1157NA carry natural amber glass, which produces the amber turn signal color directly from the bulb rather than relying on a colored lens.
The 1157 bulb carries no amber glass coating, meaning any amber color in the signal output for positions using that bulb depends entirely on the housing lens.
For the Cadillac Calais front turn signal, the 1034NA was the specified bulb for 1965-1966, 1969-1974, and 1976, while the 1157NA was specified for 1967-1968 and 1975.
For the rear turn signal, the 1157 was specified across 1969-1976, while earlier years used either the 1034NA or 1157NA depending on the model year.
Because the 1034NA and 1157NA share the BAY15d base and identical wattage ratings with the 1157, physical fitment across positions is technically possible, though the presence or absence of amber glass affects the optical output when paired with a clear lens.
The 1965 Cadillac Calais used different bulb types between its front and rear turn signal positions, with the 1034NA at the front and the 1157NA at the rear, despite both sharing the same base and wattage.
The 1968 Cadillac Calais also used different bulb types between positions, with the 1157NA at the front and the 1034NA at the rear, representing one of the few model years where the front position carried a higher-designation bulb than the rear.
All bulb types referenced in these specifications conform to ANSI standards applicable to the United States and Canada, indicating standardized dimensional and electrical tolerances across the product line.