[Red]

the switch should be set on full which stands for full range as far as cutting out that doesn't sound right and maybe a problem with the power or ground terminal try this if your fairing is off wiggle the power and then the ground wire at the terminals on the amp and see if it goes on and off it may be a loose solder joint without the amp it is hard to tell but a good place to start trouble shooting let me know if thats the problem or you can call 1800 the tube leave your number and i will return your call thanks .
Red