Fender Power Chorus problem

I have a Fender Power Chorus that is doing something strange. Whenever I play at loud volumes the chorus kicks in and out even though I have it turned off and disabled. The little red light turns green and back to red etc and I can hear the chorus kick in when it does that. I'm new to the amp so I may just have something set wrong. I have the chorus on the foot pedal turned off and the two chorus control knobs turned to zero. I love the chorus feature, but I don't need it all the time. Also the amp is a little noisy with a hum that gets louder with the amp volume. Any and all help is much appreciated! Thanks!