ok , so my rear speakers arent working. swapped the factory deck out with one i got from someone on here , still no rear speakers. then put in a kenwood i got from a friend with the adapter already on it and it worked fine in his car. guess what..... still no rear speakers. is there a connection or juntion somewhere between the deck and the rear speakers that could be disconnected or am i missing something really obvious here ? fuse box list a place for a "rear amp" fuse but there isnt one there and its obvious one never went there (no metal contacts where the fuse goes in).