TRexusBel

I recently took my 1995 GS-300 to my local shop to have the starter motor replaced and charging system checked. The motor was replaced. The techs claimed that my alternator was outputting only 10v at idle with no load, and barely above that with the RPM's up. Strange since the battery indicator light on the dash never once lit up. I deferred the suggested replacement of the alternator and took the car home for further testing with a volt meter. On the battery, with the car in idle, it read a smooth 14.2v as it should. Applying varying loads and RPM's did not change this reading. If this was an intermittent problem, will the car's battery warning gauge light up? Is it reading voltage and amperage output? What are it's thresholds? I want to believe that this very reputable shop did not screw up the test, or worse, but.... ??? Suggestions, ideas, or similar issue that any of you have experienced? Thanks!