Honda Motorcycle GL1100I Gold Wing Interstate Turn Signal Bulb Size
Honda Motorcycle GL1100I Gold Wing Interstate front turn signal bulb size 1034 and rear turn signal bulb size 1073, P21W. The replacement chart covers 1980 to 1983 production years 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 Honda Motorcycle GL1100I Gold Wing Interstate uses two distinct bulb types across its front and rear turn signal positions, with the front and rear drawing from different specifications entirely.
The 1034 bulb is an ANSI-standard dual-filament bulb rated at 12V and 21/5W, fitted with a BAY15d bayonet base. Its dual-filament design means it serves two brightness levels within a single housing, a characteristic shared with the 1157 family of bulbs, of which the 1034 is a variant.
The GL1100I Gold Wing Interstate uses the 1034 bulb in the front turn signal position across all four model years covered, spanning 1980-1983.
The rear turn signal position does not follow a single bulb specification across the production run. The 1073 appears in the 1980 and 1983 model years, while the P21W appears in the 1981 and 1982 model years.
The 1073 is an ANSI-standard single-filament bulb rated at 12V and 13W, using a BA15s bayonet base. It is a lower-wattage variant of the 1156 bulb family.
The P21W is an ECE-standard single-filament signalling bulb rated at 12V and 21W, also using a BA15s bayonet base. Its ECE classification indicates it conforms to European and international regulatory standards rather than North American ANSI standards.
Although the 1073 and P21W share the same BA15s bayonet base, their wattage ratings differ significantly, at 13W and 21W respectively, which represents a meaningful difference in electrical load and light output.
The front turn signal uses a BAY15d base, while both rear turn signal bulbs use a BA15s base. These two base types are not interchangeable, as the BAY15d features offset pins to accommodate its dual-filament design, whereas the BA15s uses a single centered pin.
Substituting the 1034 into a rear turn signal socket designed for a BA15s base would not be physically compatible, given the BAY15d base configuration of the 1034.
The alternating rear bulb specifications between the 1073 and P21W across the 1980-1983 model years indicates that replacement bulb selection for the rear position requires verification against the specific model year rather than the nameplate alone.