The Buick Apollo front turn signal requires either 1034NA or 1157NA bulb size, while the rear turn signal uses 1157 bulb size. The replacement chart covers vehicle production spanning 1973 to 1975.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1157 and 1157NA bulbs share identical electrical ratings of 12V and 21W/5W, with the dual-filament design serving both the brighter turn signal function at 21W and the lower-intensity parking or running light function at 5W.
All three bulb types used across the Buick Apollo turn signal specifications, the 1034NA, 1157NA, and 1157, use the BAY15d bayonet base, a double-contact offset-pin base that physically prevents incorrect installation orientation.
The 1034NA is described as a variant of the 1157, though it carries a distinct ANSI designation. Both are dual-filament bulbs on a BAY15d base, but the 1034NA is rated at 21/5W while the 1157 is rated at 21W/5W, indicating a possible difference in filament output despite the similar notation.
The "NA" suffix on the 1034NA and 1157NA designations indicates natural amber glass, meaning the amber color is produced by the glass envelope itself rather than by an external lens or coating.
For the Buick Apollo, the front turn signal position uses the 1034NA in 1974-1975 and the 1157NA in 1973, meaning the amber coloring in the front turn signal is produced by the bulb itself across all three model years.
The rear turn signal position uses the standard 1157 across all three model years, 1973-1975, which has a clear glass envelope rather than natural amber glass.
All bulbs listed in the Buick Apollo turn signal specifications conform to ANSI standards applicable in both the United States and Canada.
The shift from the 1157NA to the 1034NA in the front turn signal position between 1973 and 1974 represents a change in bulb designation despite both being natural amber, dual-filament, BAY15d bulbs, which may affect direct interchangeability between those model years.