Field wire not energizing when ignition on.

[Grumpa]

Need possible causes. Looking at ignition switch next.
Got the alternator, stock style, externally regulated, for '74, checked at O'Rielly's today and it checks out. Put a jumper from the batt. wire to the "field" terminal on the back of the alternator and it started pumping over 18 volts. Has a new voltage regulator and the old one that was somewhat working, didn't work either.
I put a DUI dizzy on it and right after that, the system quit charging. I've two wires left unhooked from the dizzy install, a purple one and I believe a green one. Maybe one of those needs to hook up to the distributor?

 

[TSB8C]

Here's the original stock wiring for the alternator and external regulator.



And here's the wiring for the alternator and the interconnects with the distributor.