The Subaru GL front turn signal requires a 1156, 1157, or 1034 bulb size, while the rear turn signal uses either a 1156 or 1034 bulb size. The replacement chart covers vehicle production years spanning 1975 through 1989 with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156 bulb is the most frequently specified type across the Subaru GL turn signal data, appearing in both front and rear positions for the 1982-1989 model years.
The 1156 is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base, and produced to ANSI standards for the US and Canadian markets.
Because the 1156 carries only a single filament, it serves a dedicated function in each socket rather than combining two lighting functions in one unit.
The Subaru GL front turn signal for 1980-1981 requires the 1157 bulb, which differs from the 1156 used in the same position for 1982-1989.
The 1157 is a dual-filament bulb rated at 12V with a 21W primary filament and a 5W secondary filament, fitted with a BAY15d bayonet base.
The BAY15d base of the 1157 is physically distinct from the BA15s base of the 1156. The offset pins on a BAY15d base prevent incorrect installation of a single-filament 1156 in a socket designed for the dual-filament 1157.
The 1975 Subaru GL specifies the 1034 bulb for both front and rear turn signals, making it the only model year in these specifications to use that type.
The 1034 is a dual-filament bulb sharing the BAY15d bayonet base with the 1157 and carrying the same 12V, 21W/5W ratings, and is classified as a variant of the 1157 under ANSI standards.
Although the 1034 and 1157 share the same base type and voltage ratings, they are distinct ANSI part numbers and are not universally treated as interchangeable across all applications.
The rear turn signal position uses the 1156 across all model years from 1980-1989, while the front position shifted from the 1157 to the 1156 after 1981.