electrical connections behind front bumper - DS

[millertyme]

slowly the fumigation process is reaching an end for my 87 5KT.
last week when I replaced my timing belt, I noticed that there are 3
studs and heavy gage wire connections behind the bumper cover on the
drivers side.
they are quite heavily corroded, so I left them alone for the time
being.  my question is, what do they feed, and could this be a cause of
my inability to keep the system volts above 12.5 when the headlights are
on along with the blower?
to answer a question before it is asked,. the alternator is a new 90 amp
GM (sorry if i insult anyone, but the $$ was a key factor at the time). 
I searched the site, but could not find anything about this, so any
insight from the electrical gurus would be greatly appreciated
thanks again
brian