Voltage regulator ground screw

[ogre73]

2003 base model 3.4L.
I am having a problem with my lights dimming for a bout 1 second, then coming back to full for about 3-5 seconds. They are not flickering all of the way off yet. I had a buddy of mine with the right tools check my charging system and it showed a rythmic dip that corresponds to the above pattern in the output of the alternator.
I looked at the wiring of the system on paper, and there are not too many things that could be directly wrong here. The alternator could be going bad, but that would likely be less patterned and more severe, along with starting problems. The regulator could be bad (much more likely), or the signal from the BCM to the regulator could be bad.
I got the impression that the regulator was internal to the alternator on these models, so rather than replacing the alternator (gasp! what makes them think they can charge so much!) I decided to search on here and check the connections going to the alternator.
I did an alternator search on here and found this thread http://www.automotiveforums.com/vbul...ght=alternator that references the voltage regulator ground screw. Would anyone know where that is?
Ogre

[tractorboy]

where i live some of the chain auto parts stores will test alternators for free or a small charge,
did you clean the battery posts. I am thinking it is the battery, what does the "eye" on the battery look like, is it green ? of course that is just one cell.
also do not run your car with out a battery.