Plymouth Scamp front turn signal bulbs measure 1157, 1157NA, or 1034NA in size, while rear turn signal bulbs measure 1157 in size. The replacement chart covers 1971 through 1983 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 frequently specified type across the Plymouth Scamp's turn signal positions, appearing in both front and rear applications for the 1971-1976 and 1983 model years in the rear position, and in the front position for 1976 and 1983.
All three bulb types listed in these specifications, the 1157, 1157NA, and 1034NA, share the BAY15d bayonet base, a dual-pin offset base design that physically locks the bulb into the socket at a fixed rotational position.
All three bulb types operate at 12 volts with a dual-filament output of 21W for the turn signal filament and 5W for the running light filament, making them electrically equivalent to one another.
The 1034NA is described as a variant of the 1157, meaning it shares the same base type and electrical ratings but is produced with natural amber glass rather than a clear envelope.
The 1157NA differs from the standard 1157 in that it also incorporates natural amber glass, which filters the light output to produce an amber color without relying on a colored lens.
The Plymouth Scamp's front turn signal used the 1034NA for model years 1971-1975, a bulb with built-in amber coloring, while the rear turn signal across those same years used the clear-envelope 1157, indicating the amber tint was achieved differently between the two positions.
Because the 1034NA and 1157NA are variants of the 1157 with identical base and voltage specifications, physical fitment across these three types is interchangeable, though substituting a clear 1157 for an NA-suffix bulb would alter the color output if the housing lens is not itself amber-tinted.
All three bulb types carry ANSI standardization recognized in both the United States and Canada, placing them within a regulated specification framework for base dimensions and electrical performance.