The Oldsmobile F85 front turn signal bulb size includes 1157NA, 1034NA, and 1157 options, while the rear turn signal bulb size uses 1157 or 1034 specifications. The replacement chart covers vehicle production years spanning 1961 to 1972 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.
All front and rear turn signal bulbs specified for the Oldsmobile F85 across the 1961-1972 model years share the BAY15d bayonet base, a double-contact offset-pin base design that physically locks the bulb into position and ensures correct filament alignment within the housing.
Every bulb type listed in these specifications is dual-filament, operating at 12 volts with a 21W high filament and a 5W low filament, allowing a single bulb to serve both the turn signal and parking light functions simultaneously.
The 1157 and 1034 are related bulb types. The 1034 is a variant of the 1157, meaning the two share the same base and general construction but differ in filament output characteristics, which affects their interchangeability in certain applications.
The "NA" suffix on the 1157NA and 1034NA designates natural amber glass, meaning the amber color is produced by the glass envelope itself rather than by an amber-coated lens or housing. This distinction is relevant when the vehicle's turn signal lens is clear rather than colored.
The front turn signal of the Oldsmobile F85 alternates between the 1034NA and 1157NA across model years. The 1961-1963 and 1968-1969 model years used the 1034NA, while the 1964-1966 years used the non-NA 1157 or 1034, and the 1967, 1970, and 1972 model years used the 1157NA.
The rear turn signal specification for the F85 is consistent from 1964-1972, with all those model years using the standard 1157 bulb. The 1961-1963 model years used the 1034 at the rear.
A front and rear turn signal bulb of the same model year do not always share the same bulb type. For example, the 1969 F85 specifies a 1034NA at the front and a 1157 at the rear, indicating the two positions are not interchangeable for that year.
All four bulb types listed carry the ANSI standard designation applicable to both the United States and Canada, reflecting a standardized classification system that governs the electrical and physical specifications of each bulb.
The 1157NA and 1034NA are amber-glass variants of the clear 1157 and 1034 respectively. Substituting a clear bulb for an NA-designated position, or vice versa, would alter the color output of the turn signal if the lens color does not compensate for the difference.
The front turn signal position on the F85 uses NA-suffix bulbs exclusively from 1967 onward through 1972, with the exception of 1971, which reverts to the 1034NA rather than the 1157NA used in the surrounding years.