Alt needs 12 volts from battery via fuse 4, obtained via red wire next to green wire at alt connector, in order to have output. Sounds like the connector is causing intermittent problems with both circuits although I'm not sure you could exclude faulty internal connections at alt terminals.
p.s.
Originally posted by FeiroGT:
The only sign that the alternator has stopped charging is the absence of the idiot light at startup.
Notwithstanding this statement I presume you are measuring volts at battery or seeing lights dim to indicate alt not charging.
