The right rear speaker wiring runs through (pass-through) that fuse box; but, unlikely to be the issue if both rear speaker don't work. But, anything is possible if there was a short somewhere.

 

Ok, thanks. Just trying to eliminate all possibilities before buying an old replacement radio that I can’t return. Sounds like the problem is the radio however, so that’s what I need to do I guess. Again, thank you. This forum saved me a lot of money, time, and frustration.