Subaru Baja front turn signal bulbs use 1156NA size while rear turn signal bulbs use 7443 size. The replacement chart covers 2003 to 2004 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Subaru Baja uses two distinct bulb types across its front and rear turn signal positions for the 2003-2004 model years: the 1156NA for the front and the 7443 for the rear.
The 1156NA is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base and natural amber glass, conforming to ANSI standards applicable in the US and Canada.
The natural amber glass of the 1156NA produces an amber output without relying on a colored lens, which distinguishes it from clear-glass variants in the 1156 family.
The BA15s bayonet base of the 1156NA is a single-contact fitting, meaning it is not interchangeable with dual-contact bayonet bases such as the BA15d, despite sharing the same 15mm base width.
The 7443 is a dual-filament wedge bulb in the T20 form factor, rated at 12V with a 21W primary filament and a 5W secondary filament, also conforming to ANSI standards for the US and Canada.
The dual-filament design of the 7443 allows a single bulb to serve two lighting functions, with the higher-wattage filament typically assigned to the turn signal and the lower-wattage filament to a secondary function such as a running or parking light.
The 7443 uses a wedge-style base, which differs fundamentally from the BA15s bayonet base of the 1156NA, making the two bulb types mechanically incompatible with each other's sockets.
A common substitution risk exists between the 7443 and the single-filament 7440, as both share the T20 wedge form factor but differ in filament count; installing a 7440 in a 7443 socket would disable the secondary filament function.