Im installing a small 10 watt radio on my scoot,it has a yellow wire,a red wire and a ground my question is what wire is positive for ignition the manual only has color and not if there negative or positive,i can get to work with bike off but soon as i start bike it cuts off,not off power wise just no music plays but lcd screen stays lit no sound soon as i turn bike back off and cycle power button for radio sound comes back and all is fine and body any help would be great im stumped thanks