Lincoln Mark VI front turn signal bulbs utilize 1034NA or 1157NA sizes, while rear turn signal bulbs use 1157 size. The replacement chart covers 1980 through 1983 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lincoln Mark VI front turn signal uses the 1034NA bulb for 1980 and 1982-1983, while the 1981 model year uses the 1157NA instead.
The rear turn signal position uses the 1157 bulb across all model years from 1980-1983 without variation.
All three bulb types found in these specifications, the 1034NA, 1157NA, and 1157, share the BAY15d bayonet base, meaning they are physically compatible at the socket level.
The 1034NA is described as a variant of the 1157, with both operating at 12V and carrying dual-filament ratings of 21W and 5W respectively.
The 1157NA and 1157 share identical electrical ratings of 12V and 21W/5W, differing only in that the 1157NA features natural amber glass rather than a clear envelope.
The natural amber glass on the 1034NA and 1157NA produces amber light through the bulb itself, which is relevant when the turn signal housing uses a clear or non-tinted lens.
Despite the shared BAY15d base across all three bulb types, substituting the 1034NA for the 1157 or vice versa in the rear position may affect light output characteristics, as the 1034NA is a variant with a distinct ANSI designation.
All bulbs listed are dual-filament types, meaning a single bulb serves both a running light function at the lower wattage filament and a turn signal function at the higher wattage filament.