The KTM 640 Adventure uses 232 and 5008 bulb sizes for both front and rear turn signal applications. The replacement chart covers 1998 to 2008 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 two bulb types specified for the KTM 640 Adventure's turn signals are the 232 and the 5008, both of which conform to ANSI standards applicable to the US and Canadian markets.
The 232 is a festoon-style bulb, meaning it is cylindrical in form and held in place by contact at each end rather than by a base socket. It uses an SV8.5 base and operates at 12V with a rated output of 3W.
The 5008 is a single-filament bulb with a BA15s bayonet base, which is a single-contact bayonet fitting. It operates at 12V and is classified as a lower wattage variant of the 1156 bulb type.
Because the 232 uses a festoon mounting and the 5008 uses a bayonet socket, the two bulb types are physically incompatible with each other and are not interchangeable.
For the front turn signal, the 640 Adventure used the 5008 across 1998-2000 and again from 2003-2006, while the 232 was specified for 2001-2002 and 2007-2008.
For the rear turn signal, the 5008 was specified for 1998-2002 and 2004-2007, while the 232 was used in 2003 and 2008.
In several model years, the front and rear turn signals do not share the same bulb type, meaning a single replacement bulb cannot serve both positions on those vehicles.
The 2008 model year is the only year in which both the front and rear turn signals share the same bulb type, with both positions specifying the 232.
The BA15s base of the 5008 is a single-contact variant of the BA15 bayonet family. It is distinct from the BA15d double-contact base, and substituting a double-contact bulb into a single-contact socket would result in incorrect fitment.