Hey Sonny...i have a button on my handle bar that if i push it to the right or left...a light goes on...then off...then on....then off...then on and so on...see if you can find that one!!! its amazing!
It's also possible someone put the knob on wrong. It has a tiny phillips screw in the center. Remove screw and pull knob out until it can rotate. Continue rotating until it goes back on, then try it. If it still doesn't work, turn it again until it goes on.