so i recently bought a '98 ford contour with the premium sound package, and i am having some issues. when i first got the car i noticed that if i turned the radio up, the left side speakers would basically shut off. i figured it was the deck, which i replaced with a panasonic, but still same problem. the left side will randomly kick in and work for a few minutes some days before shutting right off. my question for whoever is willing to help, could this be a problem at the stock amp, or the wiring at the speaker? and if so, would you happen to know if there is a (-) and (+) to every speaker so i could attempt to bypass the amp or install a new one. i would like to avoid tearing the doors apart if at all possible. i am eagerly awaiting a response, and will give more information if needed, thanks.