This is really strange. I tried and tried to duplicate the problem tonight with no results. My multimeter shows 14.55 volts right about idle. Even with the AC on high, stereo on, and hi beams on with engine running. I treid my best to discharge it with the key in the on position, engine off, fuel pump on plus everything previously listed, and it still sits around 12 volts. When I start it, it jumps right back to 14.55 and recharges the battery. Her is my next theory....my ps pump has been leaking for a while. I plan on changing it out this weekend. Anyway the alternator has fluid all over it. Could something have stuck open or closed for a bit due to the oil soaked throughout the alternator? Never have been into a yota alt so I have no idea whats in there---I am assuming these are internally regulated??