I had a 2000 KW W900, with similar problems. It was all under the hood in the fenders. Bad grounds, bad connections. Over the years, the calcium chloride they spray on the roads along with the salt had rotted out just about every conductor. Inside the insulation! no breaks in the conductor, just oxidized copper turned to dust. I took a weekend, pulled out all the wire from headlights, turn signals and every other light in both fenders and just replaced all of it. I did not use KW harnesses, just two and three conductor automotive cable that was jacketed along with heat shrink butt splices. It was not too expensive, it cured everything and I quit messing with lighting issues every weekend. I should have done it sooner. Dumb on me!