The Honda Motorcycle VTX1800N uses 12496 and PY21W bulb sizes for both front and rear turn signal applications. The replacement chart covers 2004 through 2008 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 VTX1800N uses two distinct bulb types across its turn signal positions: the 12496 and the PY21W. Both operate at 12V, making them electrically compatible with the motorcycle's standard electrical system.
The 12496 is a halogen bulb designated under Philips and Osram part numbering systems, intended for specialty automotive applications. It is rated at 12V.
The PY21W follows the ECE (Economic Commission for Europe) standard, which is recognized across European and worldwide markets. It is a single-filament amber bulb rated at 12V and 21W, fitted with a BAU15s bayonet base.
The BAU15s base of the PY21W features an offset pin arrangement, which physically prevents it from being inserted into sockets designed for other bayonet-style bases such as the BA15s. This offset is a deliberate design feature to avoid incorrect bulb fitment.
For the front turn signal on the Honda Motorcycle VTX1800N, the 12496 bulb was specified for the 2006-2008 model years, while the PY21W was specified for 2004-2005.
The rear turn signal position shows a non-uniform bulb specification across the production run. The 2004 model year uses the 12496, the 2005-2007 model years use the PY21W, and the 2008 model year returns to the 12496.
Because the front and rear turn signal positions do not share the same bulb type across all model years, the 12496 and PY21W are not interchangeable as direct replacements for one another without confirming the specific year and position.
In the 2006-2008 model years, the front turn signal uses the 12496, while the rear turn signal specification differs by year, meaning both bulb types may be present on the same motorcycle depending on the year.