Honda Motorcycle VTX1300R/S/T Turn Signal Bulb Size
Honda Motorcycle VTX1300R/S/T front turn signal bulbs use a P21/5W size while rear turn signal bulbs use a P21W size. The replacement chart covers 2003 through 2009 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 VTX1300R/S/T uses two distinct bulb types across its turn signal positions: the P21/5W at the front and the P21W at the rear, a fitment pattern that remains consistent across the 2003-2009 model years.
The P21/5W is a dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, which allows a single bulb to serve two lighting functions simultaneously.
The P21/5W uses a BAY15d bayonet base, an offset two-pin fitting designed to prevent incorrect installation by ensuring the bulb can only be seated in one orientation.
The P21W is a single-filament bulb rated at 12V and 21W, dedicated solely to turn signal operation at the rear of the motorcycle.
The P21W uses a BA15s bayonet base, a single-pin fitting that is physically incompatible with the BAY15d base of the P21W/5W, making the front and rear bulbs non-interchangeable despite their similar wattage ratings.
Both the P21/5W and P21W conform to ECE standards, a regulatory framework recognized across Europe and numerous other markets worldwide.
The base type difference between the front and rear bulbs is a critical fitment consideration, as the BAY15d and BA15s sockets are not compatible with each other even though both use a 15mm bayonet cap format.