Ford Fiesta front and rear turn signal bulbs utilize sizes 3157NA, 1157, 3157, and 1156 across various model generations. The replacement chart documents bulb specifications spanning 1978 to 2019 production years.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Ford Fiesta front turn signal uses the 3157NA bulb for model years 2014-2019, while earlier 1978-1980 models use the 1157 bulb, indicating a significant design change between those two production periods.
The 3157NA is a dual-filament T25 wedge bulb rated at 12V with a 27W high filament and 7W low filament. The "NA" designation denotes natural amber glass, which produces an amber signal output without relying on a colored lens.
The 3157 and 3157NA share the same T25 wedge base and 12V/27W/7W electrical ratings. The sole distinction is that the 3157 has a clear glass envelope, while the 3157NA has an amber-tinted envelope.
The 2019 Ford Fiesta rear turn signal uses the 3157 rather than the 3157NA specified for 2014-2018 rear positions. Substituting one for the other affects the color output at the lens, which may or may not meet regional lighting regulations depending on lens color.
The 1157 bulb, used in the 1978-1980 Fiesta front turn signal, features a BAY15d bayonet base. This base type has two offset pins at different heights, which prevents incorrect installation orientation.
The 1156 bulb, used in the 1978-1980 rear turn signal, is a single-filament design with a BA15s bayonet base rated at 12V and 21W. Unlike the dual-filament 1157 used at the front, the 1156 serves only one lighting function per socket.
All four bulb types in these specifications conform to ANSI standards applicable in both the United States and Canada, meaning they share standardized base dimensions and electrical characteristics across those markets.
The 3157NA and 1157 are both dual-filament bulbs, but they are not interchangeable. The 3157NA uses a T25 wedge base while the 1157 uses a BAY15d bayonet base, making them physically incompatible with each other's sockets.
The 1157 and 1156 share the same 12V operating voltage and similar bayonet-style bases, but the 1157 has a BAY15d dual-contact base for two filaments while the 1156 has a BA15s single-contact base for one filament. These differences make them non-interchangeable.