Your problem is likely to be an alternator fault, but before you go any further, make a temporary connection between the main alternator terminal and the battery POSITIVE (+) terminal and re test with your multi-meter -You should be getting about 14 Volts.
If there is no improvement, link the small alternator terminal to the main terminal and again re-test. If still no improvement, the alternator needs either replacing or repairing.
Regards.
If there is no improvement, link the small alternator terminal to the main terminal and again re-test. If still no improvement, the alternator needs either replacing or repairing.
Regards.