My 2006 KTM 450EXC headlight unit simply uses three individual push-on female connecters which push directly onto the headlight bulb spade tabs. My bike has a homemade harness but I think the individual push ons are standard. The bike lighting system has been converted to DC using a Trail Tech stator and regulator.
I believe most all KTM's were delivered with an AC lighting system, thus will require conversion to DC. One can go the Trail Tech route, or for less money rewire the stock stator (easily done) and purchase a small regulator.