more voltage problems

[tyrone27 at gmail.com (Derrick floyd)]

well I ran in to more voltage problems tonight.  was driving up the
street and the voltage dropped from 14V to 11.8  and it stayed there. 
I have to cut every thing off to get it to go to 12.3  i cut it off
and restarted it and it was working fine again.  while it was running
I unhooked the battery and it ran on its own for a while.  then when
it after I hooked up the battery and everything and was driving it did
it again voltage would go from 14V to 13.8 then to 12.5 the to 11.8 
keep going up and down.

Any suggestions?  I think its the alternator or the B+  wire coming
from teh alternator to the starter.   What gauge B+ wire are you guys
running?  I'm going to try to replace the alternator and B+ wire
wednesday.