I replaced to voltage regulator today and still have the same problem. I checked grounds to the chassis, engine, alternator, voltage regulator and everything looks good. I checked the wiring to the voltage regulator and verified I have a two good connections from the alternator and a good connection from the battery. All connections appear to be on the correct pins. I also have a single connection from the voltage regulator to a resistor(?) or some single componet that is bolted to the chassis below the regulator. I have a good battery connection to the alternator, but I did note that I have 12.5v on the blk/wht wire with the ignition off and the voltage regulator is still warm to the touch after the car has been sitting idle.

My symptoms still are 12.5 volts idle measured at the battery and on the voltage gauge connected to the fuse panel. Once the car is started the voltage jumps to 17-17.5v and will increase to 18v when I hit the accelerator.