Electrical Help!

[SRrunner]

OK this is kinda trying to figure out what the issue is so i was hoping someone could throw out a few ideas i have a SR20det with a nissan quest alternator, with a bigger ground wire, and a 175 amp fuse on the Alt. (ive went threw 4 stock alternators so i and a bit caucious about it) with 2 oddesy batterys (i have a big system) this morning when i started my car to go home it was acting a bit funny (low volts) but i made it home then went to go out and i was running on 9.9 volts so somewhere the Alternator is not working (i think) i checked all the wiring and fuses everything is good. if you have any idea please let me know