Brake lights dont work on my 2001 kawasaki vulcan motorcycle

Not sure if you have fuses for that particular function on that bike, but check there first. Then check to make sure the wires are all connected to the back light. The rear brake has a switch (usually a spring is attached to the brake lever) that pulls down when you push down, tripping the light to go, and the hand controls have a similar switch, although when you pull the brake in, it lets a spring-loaded button push out, which then turns the light on. It might be as easy as you just have a brake light out. The bulbs in back usually have dual filaments in them, your running light may work but your brake light might be out. Hope this helps a little.

Bruno