The American Motors Ambassador front and rear turn signal bulbs utilize either 1157 or 1034 size specifications depending on production year. The replacement chart covers 1958 to 1974 model 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 American Motors Ambassador uses two bulb types across its turn signal history: the 1034 for model years 1958-1963 and the 1157 for model years 1964-1974, applied identically to both front and rear positions in each respective period.
Both the 1034 and 1157 are ANSI-standardized bulbs recognized in the United States and Canada, meaning they conform to a defined set of electrical and physical standards shared across the North American automotive market.
Both bulbs are dual-filament types, which allows a single bulb to serve two lighting functions simultaneously, typically a brighter filament for the turn signal flash and a dimmer filament for a steady running or parking light.
Both the 1034 and 1157 use a BAY15d bayonet base, a two-pin offset base design where the two pins are positioned at different heights to ensure correct orientation during installation and prevent reverse fitting.
Both bulbs operate at 12 volts with a 21W/5W power rating, where 21 watts corresponds to the high-intensity turn signal filament and 5 watts to the low-intensity filament.
The 1034 is classified as a variant of the 1157, meaning the two share the same base type and general electrical characteristics but are not fully interchangeable due to differences in their filament specifications and pin offset tolerances.
Because the 1034 and 1157 share the BAY15d base, physical insertion into a socket designed for one may be possible with the other, but the electrical output difference between the two variants makes substitution a fitment concern on the American Motors Ambassador for model years where the 1034 is specified.