The American Motors Spirit front turn signal requires a 2057NA, 1034NA, or 1157 bulb size, while the rear turn signal uses a 2057 or 1157 bulb size. The replacement chart covers vehicle production years spanning 1979 to 1983.
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 American Motors Spirit use the BAY15d bayonet base, meaning every bulb across all model years shares the same base type.
The BAY15d base is a dual-contact bayonet fitting, which is required to support the two separate filaments present in all bulbs listed for this vehicle.
The 1157 is the most frequently appearing bulb across these specifications, serving as the front turn signal for the 1979 Spirit and the rear turn signal for the 1979-1982 model years.
The 1157 operates at 12V with a dual-filament output of 21W and 5W, where the higher wattage filament serves the turn signal function and the lower wattage filament serves a secondary lighting function such as running or parking light duty.
The 1034NA was specified for the front turn signal on the 1980-1982 Spirit. It is a variant of the 1157 with natural amber glass and a reduced wattage of 21W/5W at 12V.
The natural amber glass on the 1034NA produces an amber signal output directly from the bulb itself, rather than relying on a colored lens to achieve the required turn signal color.
The 2057NA was specified for the front turn signal on the 1983 Spirit. It is the amber-glass counterpart to the 2057 and operates at 12V with a higher output of 26.9W and 8W compared to the 1157.
The 2057 was specified for the rear turn signal on the 1983 Spirit. It shares the same 26.9W/8W output at 12V as the 2057NA but uses a clear glass envelope rather than natural amber glass.
The 2057 and 2057NA are described as brighter variants of the 1157, with the high-beam filament drawing 26.9W versus the 21W of the 1157, which reflects a measurable increase in light output.
Although the 1157 and 2057 share the same BAY15d base, substituting one for the other would result in a wattage difference, as the 2057 draws more power on both filaments than the 1157.