Honda Motorcycle VTR250 Interceptor Turn Signal Bulb Size
Honda Motorcycle VTR250 Interceptor front and rear turn signal bulbs use 1073 and P21W bulb sizes. The replacement chart covers 1988 to 1990 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 Honda Motorcycle VTR250 Interceptor turn signal specifications reference two bulb types across the 1988-1990 model years: the 1073 and the P21W.
Both the 1073 and P21W share a BA15s single-contact bayonet base, meaning the physical mounting interface is identical between the two types.
Despite the shared base, the 1073 operates at 13W while the P21W operates at 21W, a difference of 8 watts that affects load on the turn signal flasher relay.
The 1073 follows the ANSI standard used in the United States and Canada, while the P21W follows the ECE standard used in Europe and internationally, reflecting regional market variants of the VTR250 Interceptor.
The 1073 is a lower wattage variant of the 1156 bulb, sharing the same BA15s base and single-filament construction but drawing less current.
Both bulbs operate on a 12V electrical system, consistent with standard motorcycle electrical architecture of that period.
On the 1990 Honda Motorcycle VTR250 Interceptor, the front turn signals use the 1073 while the rear turn signals use the P21W, meaning the front and rear positions are not interchangeable by bulb type that year.
The 1988 model presents the reverse configuration, with the front turn signals using the P21W and the rear using the 1073, again making front and rear positions non-interchangeable by bulb type.
Substituting a P21W in a socket specified for a 1073 would introduce a higher wattage draw, which may affect flasher relay timing since most thermal and electronic flashers are calibrated to expected load values.
The 1989 model specifies P21W for both front and rear turn signal positions, making the bulb type uniform across all four turn signal sockets that year.