The Buick Sportwagon front turn signal bulb size includes 1157NA, 1034NA, or 1157, while the rear turn signal bulb size is 1157. The replacement chart covers 1964 through 1972 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 1157 bulb is the most widely used type across these specifications, appearing in all nine model years for the rear turn signal position of the Buick Sportwagon and in the 1964 front turn signal position.
All three bulb types listed, the 1157, 1157NA, and 1034NA, share the BAY15d bayonet base and operate at 12V with a dual-filament configuration rated at 21W and 5W.
The dual-filament design of these bulbs allows a single unit to serve two lighting functions, typically combining the turn signal function on the higher-wattage filament with a lower-intensity running or parking light on the 5W filament.
The 1157NA and 1034NA variants differ from the standard 1157 by incorporating natural amber glass, which produces an amber light output without relying on a colored lens or housing.
The 1034NA is described as a variant of the 1157, sharing its voltage and wattage ratings while featuring the natural amber glass construction of the NA designation.
The front turn signal of the Buick Sportwagon used the 1157NA for the 1965-1967 and 1972 model years, while the 1034NA was specified for the 1968-1971 model years.
All three bulb types conform to ANSI standards applicable in both the United States and Canada, indicating a standardized fitment specification across North American markets.
Because the 1157NA and 1034NA share the same BAY15d base and electrical ratings as the standard 1157, physical interchangeability is possible, though the amber glass coating on the NA variants affects light color output and may interact differently with the vehicle's lens color.