I just purchased a 1995 s-10 blazer ls, it had an after market sony stereo when I got it. The stereo lights up fine, but with no sound. I checked all the wiring, everything was good. So I put in a pioneer stereo that I knew worked fine, and same problem. The stereo has all the appearances of working, but no sound. The speakers all seem to be hooked up, what could be the problem. I'm at a loss!

 

When you say the wiring is fine, do you mean that you checked all the factory wiring going into the wiring harness? Have you talked to the previous owner to see if they had the same problem and to find out what happened when the sound went out?