Honda Motorcycle NT650 Hawk GT Turn Signal Bulb Size
Honda Motorcycle NT650 Hawk GT front turn signal uses a 1034 bulb size, while the rear turn signal requires either a P21W or 1073 bulb size. The replacement chart covers 1988 to 1991 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 Honda Motorcycle NT650 Hawk GT uses two distinct bulb standards across its turn signal positions: the ANSI standard, common in the US and Canada, and the ECE standard, used in Europe and worldwide markets.
The 1034 bulb is specified for the front turn signal position across all four model years, 1988-1991, making it the most consistently applied bulb type in these specifications.
The 1034 is a dual-filament bulb operating at 12V with a 21/5W output and a BAY15d bayonet base. Its dual-filament design means it is capable of serving two lighting functions from a single housing, typically combining a brighter filament for signalling with a dimmer one for running light duty.
The 1034 is classified as a variant of the 1157, a widely used ANSI automotive bulb. The two types share the same BAY15d base and dual-filament configuration, though they differ in their precise electrical ratings.
The rear turn signal specification changed between the 1988 and 1989 model years of the Honda Motorcycle NT650 Hawk GT, shifting from the 1073 bulb to the P21W bulb.
The 1073 bulb, used in the 1988 rear turn signal position, is a single-filament ANSI bulb with a BA15s bayonet base, rated at 12V and 13W. It is described as a lower wattage variant of the 1156.
The P21W, used in the rear turn signal position for 1989-1991, is also a single-filament bulb with a BA15s bayonet base, but it operates at a higher output of 21W. It conforms to the ECE standard rather than the ANSI standard.
Although the 1073 and P21W bulbs share the same BA15s bayonet base type, their wattage ratings differ significantly at 13W and 21W respectively, and they belong to different regulatory standards. This makes them non-interchangeable without accounting for the electrical load difference.
The BAY15d base used by the 1034 front bulb has an offset pin configuration that physically prevents it from being inserted into a BA15s socket, which is used by both the 1073 and P21W rear bulbs. The front and rear sockets are therefore not cross-compatible.
All bulbs specified across both positions and all model years operate on a 12V electrical system.