On the way to get my wagon inspected yesterday and it dies while at a red light....Long story short, I get it running today with a jump start from my wife's vehicle and check the voltage at the battery with my VOM and it starts off at 13.52 at idle and slowly started going down by .01 about every minute, after that I hold the RPM's at 1500 and it lingers around 13.46 -13.47 and stayed like that for the 5 minutes I held it there, Finally I let it go back to idle and almost immediately it starts going down by .01 but a bit fast than before. At this point I decided to call it quits and went over to turn off my jumper car and walk back to the Mercedes (5 feet to and back) and as I am approaching it the idle starts getting erratic (slowing/surging) so I quick put the VOM on it and it was all over the place 13.30,12.72,13.18,11.97,12.48 and did this for about a minute (maybe a bit less) and shut it off.

I got some advice but that was on a lot less information than what I gave here. I thought it was the Alternator and this person said to check out the Voltage Regulator first because most of the time it is a voltage regulator issue and not the alternator. Now up until my testing the voltage at the battery with it running I just did a lot of reading (A LOT OF READING) and it seems that people had issues with bad grounds, shorting wires, and a couple of other things that I cannot remember.
I am hoping some of you guys after reading this have an idea of where to start......To me it is still a voltage regulator and maybe an alternator issue, I am thinking of just buying an 80A version and fix to problems at once. If there is anything else that could be causing voltage drop and then the erratic voltage later on please let me know.