I have a 2000 mustang convertible and when i turn on the headlights (with the car running) I get a warning bell like the one you would get when you turn the car off with the lights still on or a door open or something. I'm not very familiar with mustangs, this is actually my first one. The person i bought the car from said that they unplugged the rear view mirror because the lights wouldnt turn off. Does anyone have an idea of what may be causing this?