Troubleshooting radio problem

I've got no radio and it's been that way for a while. I could break down and take it to someone and have a new system installed. But I like the look of the original and I don't want to spend a lot of money on this. When the sound disappeared, I had lights on the radio so it couldn't be the fuse. I checked anyway. The radio was a boneyard replacement with a broken tape deck so it wasn't any spring chicken - I found a new used one, really clean looking - still no sound. I've checked a couple of speakers with the crude 9 volt battery test - the current makes them jump and click, not sure if this means they're still functional. I'm at a loss on how to find the problem. I'm going to try to find a new fader switch, the dial above the radio next to the hazard and rear window heater switches. I'm guessing if that somehow went bad the circuit might be interrupted. Sorta desperate, I'll admit.

You are on the right track. Have you tried the radio(s) out of the car on test speakers? That way you will know if it is the unit or the car.

Originally Posted by BMWFatherFigure

You are on the right track. Have you tried the radio(s) out of the car on test speakers? That way you will know if it is the unit or the car.

Next time at the boneyard, I'll find some E30 with the radio out and harvest some of the jacks that insert into the back of the unit, the speaker wire jacks, and any other that might be useful. Would make a bench test easier. This is a perplexing problem, I'm surprised that it's such a bugger to get to the bottom of.