maxthrottl

I'm having trouble with the Left rear speaker in the '93 SC400.
When i adjust the balance and fade to the left rear corner, almost no sound at all.
Every now and then the speaker works! and the radio sounds just like new although this is only less than 10% of the time so I'm guessing that the actual speaker is OK. I assume it's either a loose wire harness or connector or the actual Receiver is suspect. The speaker starts working all by itself, (not after hitting a bump) so I'm not hopeful about the loose wire theory. I checked all of the connections at the speaker and at the AMP in the trunk. I even took the console apart and inspected the connectors in the back of the receiver everything looks good and tight and nicely built I might add. I think that one of the channels in the AMP is on the way out.
The receiver is the Nackamichi Premium model with integrated Tape player (It ate a tape a few years back so that doesnt work either) Can anyone recommend a good, honest radio repair facility that could restore this puppy to working condition? Thanks.