Subaru GF front and rear turn signal bulbs utilize 1157, 1034, and 1156 bulb sizes depending on location and model variant. The replacement chart covers 1975 through 1979 production 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 GF uses three distinct bulb types across its front and rear turn signal positions: the 1157, the 1034, and the 1156, all of which conform to ANSI standards applicable in the United States and Canada.
The 1157 and 1034 are both dual-filament bulbs rated at 12V with a 21W/5W output, meaning each bulb serves two brightness levels within a single housing, typically one filament for running light duty and one for signaling.
Both the 1157 and 1034 use a BAY15d bayonet base, which is an offset twin-pin base designed to prevent incorrect installation by ensuring the bulb can only be seated in one orientation.
The 1034 is classified as a variant of the 1157, sharing the same base type, voltage, and wattage ratings, though the two are distinct ANSI part numbers and are not guaranteed to be interchangeable in all applications.
The 1156 is a single-filament bulb rated at 12V and 21W, and it uses a BA15s bayonet base, which is a single-pin base distinct from the twin-pin BAY15d base found on the 1157 and 1034.
Because the BA15s and BAY15d bases are physically different, the 1156 is not interchangeable with the 1157 or 1034, even though all three operate at 12V.
In the 1979 Subaru GF, the front turn signal uses the 1157 while the rear turn signal uses the 1156, meaning the front and rear positions require different bulb types in that model year.
In the 1975 Subaru GF, both the front and rear turn signal positions share the same bulb type, the 1034, indicating a uniform fitment across both positions for that year.