no sound from stereo

I did a search and didn't find my problem.
Have a 2000 XJ with regular stereo and it works but I have no sound thru any of the speakers. It has no amp under the rear seat.
Any common problems with this? I can't imagine all 4 speakers being blown.
I did try an old speaker in the rear and it didn't play, but I dont know if that speaker was any good.
I'm thinking a wire problem somewhere any idea where to look?

First thing I would do is pull out the radio and check if wiring harness is fully connected at radio. If yes, plug your old speaker directly at your radio to see if radio still give something out to the speaker. Check each of the four speaker output. If speaker works on all four outputs, next thing to do is to check wiring and speakers. You need to identify each pair of wires for each speaker. Next, using a 9 volt battery, connect one wire to the battery and while having the other end of the wire in your hand, repedetly touch the battery. You should ear a "HUMMM" and "TOCK" "TOCK". It's hard for me to describe exact sound but if you try it on your old speaker, you'll see what I mean. That being said, you'll be able to determine if your cabling and speakers are OK.

Best of luck.