alternator excitor wire from ign switch...

67Dart273 is correct. He is also our resident electrical expert, so you should follow-up on anything he posts and be grateful. The alternator diagram in your link is for the Motorola design used in many GM's.

Mopar alternators are quite different and much simpler to understand and wire. My 80's Mercedes has the Motorola style and it confused the heck out of me until I figured out how the D+ "exciter" lead worked. Mine stopped charging since I replaced the dash bulb with an LED which didn't provide enough "boot up" current. Mopars don't have such issues.