Plymouth Duster front turn signal bulbs utilize 1034NA or 1157NA size specifications, while rear turn signal bulbs require 1157 size. The replacement chart covers 1970 through 1976 production years 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.
The Plymouth Duster's turn signal bulbs across all listed years fall within three ANSI-standard types: 1034NA, 1157NA, and 1157, all of which share the BAY15d bayonet base and dual-filament construction.
The BAY15d bayonet base is a double-contact offset-pin base, where the two pins are positioned at different heights to prevent incorrect installation orientation.
All three bulb types operate at 12 volts with a dual-wattage rating of 21W/5W, where the higher filament serves the turn signal function and the lower filament serves a secondary function such as parking or running light.
The 1034NA is a variant of the 1157, sharing the same BAY15d base and 12V/21W/5W ratings, but it features natural amber-tinted glass rather than a clear envelope.
The 1157NA shares the same specifications as the 1034NA, including the natural amber glass and BAY15d base, and is functionally distinct from the clear 1157 only in its factory-tinted envelope.
The rear turn signal position on the Plymouth Duster used the 1157 across all model years from 1970-1976, indicating a consistent clear-envelope bulb for that position throughout the entire production span covered.
The front turn signal position on the Plymouth Duster (1970 and 1972-1974) used the 1034NA, while 1971 and 1975 used the 1157NA, and 1976 returned to the 1034NA, reflecting variation across model years in the front position specifically.
Because the 1034NA is a variant of the 1157 and all three types share the BAY15d base and identical voltage and wattage ratings, physical fitment across these types is mechanically compatible, though the amber glass of the NA variants produces color at the bulb level rather than relying solely on a colored lens.
Substituting a clear 1157 in a front turn signal position specified for a natural amber variant may affect the color output of the signal if the housing lens is also clear, as the amber tint would no longer be present at the bulb itself.