Stop and focus. I'm guessing that you're worried about making another mistake, and that's keeping you from reading carefully.
From my previous post, "with the key in OFF, you should have an open line on the L or "lamp" wire on the T plug to the white wire, and it should have continuity when the key is ON. That is because it is a switched source."
S - Sensing battery voltage. When the battery voltage drops, the voltage regulator excites the field to raise the output voltage of the alternator.
L - Lamp: On a lot of old cars, there is a light to indicate a charging failure. Under normal conditions, the voltage is the same on both sides of the light. When the alternator starts to fail, the voltage drops on the alternator side, and the bulb lights up. When the car is off, the alternator is not producing any power (and therefore no voltage), so if you are not using a switched source, the charging light would be lit all of the time.
By the way, these are the alternators I'm used to playing with. The alternator is inside the red rectangle. This one is a 16 cylinder engine with quad turbos. It will put out over 2 megawatts of power. The usual voltage output is 4.16kV to 14.4kV.