The Subaru GL-10 front and rear turn signal bulbs both utilize a 1156 size bulb for proper illumination. The replacement chart covers 1985 to 1989 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 GL-10 uses the 1156 bulb for both the front and rear turn signals across the 1985-1989 model years.
The 1156 is a single-filament bulb, meaning it is dedicated to one lighting function rather than serving dual purposes such as combined stop and turn signal operation.
The 1156 operates at 12 volts and 21 watts, which is consistent with standard automotive electrical systems of that era.
The 1156 uses a BA15s bayonet base, a single-contact fitting that locks into the socket with a twist.
The 1156 conforms to ANSI standards and is specified for use in the United States and Canada.
Because the same bulb size applies to all five model years in both the front and rear positions, a single 1156 bulb serves all four turn signal sockets on the GL-10 throughout the entire 1985-1989 production run.
The BA15s base designation indicates a 15mm base width with a single contact pin, and substituting a BA15d double-contact base bulb would result in an incompatible fit even if the physical housing appears similar.