So I'm finally starting to get to the bottom of my alternator not charging the battery. I purchased a new alternator with an internal regulator. I then made the connections to remove the voltage regulator (blue to brown and yellow to orange). Still the alternator was not charging the battery. Finally, I traced the brown wire, which used to go to the regulator, inside the car and found that it did not lead anywhere and was just open hot lead. My understanding, from wiring diagrams, is that the brown wire needs to be hooked up to the ignition switch. Getting to the ignition switch seems like a difficult task. Could I just connect it to an ign post on the fuse box?
The light (if you have an idiot light) acts as a current limiter for the brown wire sense circuit. It has power only with the ignition on. On vehicles with no idiot light (gauges), there should be a resistor in the line to act as the current limiter. Full 12v without a current limiting resistance sets you up to possibly damage the sense circuit with too much current flow.