Honda Motorcycle VTX1800S front and rear turn signal bulbs use a 12496 or PY21W bulb size. The replacement chart covers 2002 through 2006 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 VTX1800S uses two distinct bulb types across its front and rear turn signal positions: the 12496 and the PY21W.
The 12496 is a halogen bulb designated under Philips and Osram part numbering systems, rated at 12V and intended for specialty automotive applications.
The PY21W is an ECE-standard single-filament amber bulb rated at 12V and 21W, fitted with a BAU15s bayonet base, and is common in European and worldwide automotive markets.
The BAU15s base on the PY21W features offset pins, which physically prevents it from being interchanged with bulbs using a standard BA15s base, making socket compatibility a relevant fitment consideration.
The front turn signal position on the Honda Motorcycle VTX1800S (2003-2006) does not use a single bulb type across all model years, as the 2002 and 2004 model years specify PY21W while the remaining years specify 12496.
The rear turn signal position uses the 12496 for the 2002-2005 model years, while the 2006 model year specifies the PY21W instead.
Because the front and rear positions can call for different bulb types within the same model year, the two positions are not interchangeable without confirming the specification for each location individually.
In the 2006 model year, the front turn signal specifies 12496 while the rear specifies PY21W, meaning both bulb types are required simultaneously on a single motorcycle.
In the 2005 model year, both the front and rear turn signal positions specify the 12496, making it the only year in the dataset where a single bulb type covers both positions.