Honda Motorcycle VT750 Shadow Turn Signal Bulb Size
Honda Motorcycle VT750 Shadow front turn signal bulbs use P21/5W size while rear turn signal bulbs use P21W size. The replacement chart covers 1998 through 2020 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 VT750 Shadow uses two distinct turn signal bulb types across its front and rear positions: the P21/5W for the front and the P21W for the rear, both conforming to ECE standards recognized in Europe and worldwide.
The P21/5W is a dual-filament bulb, meaning it carries two separate filaments within a single envelope, allowing it to serve more than one lighting function from the same housing. It operates at 12V and draws 21W on its primary filament and 5W on its secondary filament.
The P21W is a single-filament bulb rated at 12V and 21W, dedicated to one lighting function per position. Its simpler internal construction reflects its role as a single-purpose rear turn signal source.
The P21/5W uses a BAY15d bayonet base. The BAY15d designation indicates an offset dual-contact base, where the two pins are positioned at different heights to prevent incorrect installation of the bulb in the wrong orientation.
The P21W uses a BA15s bayonet base. The BA15s designation indicates a single-contact base with symmetrically placed pins, which is a common base type across a wide range of single-filament automotive and motorcycle signal bulbs.
Because the P21/5W and P21W share the same 21W primary output but differ in base type and filament count, the two bulbs are not interchangeable with each other. The BAY15d and BA15s bases are physically incompatible, and the housings for each position are designed to accept only the specified base type.
The front turn signal position of the Honda Motorcycle VT750 Shadow specifies the P21/5W across the full 1998-2020 model range covered in these specifications, indicating a consistent fitment requirement throughout that period.
The rear turn signal position specifies the P21W across the same 1998-2020 range, maintaining a uniform single-filament fitment requirement at the rear throughout that span.