Hello, I have a 2007 GMAC Sierra 1500. While driving the battery light came on and the dash displayed 'charging system failure'. The battery was tested and it tested good. Charging system tested while vehicle was running and it failed, no charge. Alternator was removed and bench tested and it passed all test. Reinstalled alternator was reinstalled, checked all terminals and wire connections to make sure they were secure. Dash continues to display 'charging system failure'. The dash volt meter shows that it is charging at 12 volts.