Hey, I just bought a used Honda that came with a Kenwood KDC-X591 with the car's stock speakers (2 front, 2 rear) and two mini speakers on the dash. After testing out the system, I noticed that both rear speakers weren't working. So I read through the Kenwood manual and found out that I needed to disable "Dual Zone". I did that and now all the speakers are playing fine except the right rear speaker. I can see both rear speakers from the trunk and both have nice and firm connections.
Where can I check to find the problem? Is it possible that the original owner didn't connect the right rear speaker to the head unit? Could there be a setting that is disabling one of speakers?
btw, in the trunk I also see something that looks like amp connections (RCA wire, a thin blue wire, and a thick red wire).
