i had an kenwood aftermarket radio with a kenwood 4 channel amp and subs installed in my car 2 years ago. Recently my car battery went bad and i replaced it with a new one. The problem is when i don't start the car there and only turn the key until the car accessories come on there is no sound from my speakers. Also when the car is started and the radio is on and i roll down the windows the volume will start cutting in and out. Another problem is when I'm driving the sound will also cut out or when i press the car brake it cuts out. The sound will also cut out when i turn the volume up higher. it doesn't do it all the time but it seems like the problem is becoming more frequent. Any suggestions on how to fix this problem?