What voltage should the alternator put out at idle? What voltage when reved up?

Have the battery tested both with a hydrometer and high rate discharge test to see if it is good (probably not. At rest voltage for a fully charged "good" battery is 12.6 volts an alternator that is charging will read 14.6 approx across the battery with the engine running. also take a reading at the large B+ alternator terminal and see if the voltage is higher there indicating bad connections.