With the engine running I get 14.4 volts at the battery. But as soon as I turn on all the various electrical loads that voltage drops down to 11.8 volts. I've tried another battery and it's still the same so one could easily assume it's the alternator.
However, there's another bit I need to tell you. The alternator won't start charging until it's been over 3k rpm at least once. This is because the smaller "exciter" wire has a loose connection "internally". Does this wire tell the alt when there's increased demands on the battery?