i need some help here i have a 1991 accord and i got a sub and after market speakers in it, but today my friend noticed one is not working, so he had a spare speaker in his car and we tried hooking it up to see if it work. no luck so he was messing with the radio and found out it was on just the right side so he switches it over to just the left side and then there was no sound coming from the speakers at all (showing that just the right side speakers are working) so if any one could help me out here or know anything about wiring and has any ideas would be great thanks for any help in advance.

 

P.S. all sound system stuff in the car was there from when i bought it, and yes the speaker that was not working was wired up straight to the original wires