Weeds,
Ken figured it out. They make plastic caps that snap over the DA plug hole when the alternator is equipped with a voltage regulator capable of one wire service...I have never heard of one being riveted on though.
Your alternator will "self excite"...electrically, it just takes a quick pop of the throttle. This is what Ken meant I'm sure.
While dinking around on a Delco parts site, lo and behold, I found a add-on deal to make a 10DN alternator into a "faux SI" unit. It's a little solid state regulator with a couple of pigtails hanging out of it.
So my previous statement that the old external kind can't be converted was incorrect...not the first time.
The picture you linked shows a brand new rebuilt, nice looking unit all setup for single wire service. Good luck.
Stuart
