My left speakers recently stopped working, so i replaced all 4 speakers with audiobahns. the 2 right ones sound great but the left ones still dont work at all. all wiring looks correct. it is the stock radio. i pulled it out of the dash and moved the wires round a bit...unplugged them and replugged them in. im planning on buying a new head unit but i want to make sure the wiring is fine before i go out and spend the money...any suggestions are greatly appreciated...thanks in advance