I bought a used MB that the original owner installed a Rockford Fosgate Punch 440 amp in the trunk in 1995. So the amp is close to 10 years old. Never had a problem until today when I noticed the subs in my doors weren't working. Tried adjusting the balance and fader to isolate the subs, but they are on the same channel with my rear speakers. I think my amp is "going out" if there is such a thing. Is there any way to test or a fuse panel for the amp where I can check something visual. Any suggestions appreciated. I won't even be offended if you start the post with "Dave, you Dumb A--". I'm no audiophile.