Two wire and three wire converters???

[max7]

Got a question, I am going to replace the Triad-Ultrad TV 750-2 Converter Charger in my 65' Globetrotter with a Progressive Dynamics, Inc. Inteli-Power 9245 Converter with charge wizard. This converter will be an easy swap It has two wires Red + and White - ....fine.
Here is my question: I would like to install the Triad-Ultrad in My 66' Safari because it does not have a converter. BUT, the Safari has three wires Red, White, and Black. How can I hook the two wire Triad-Ultrad up safely? Leave some thing disconnected?
Here is a pic of my 66' Safari wiring:
Thanks!

[Zeppelinium]

When I removed my old converter in the '77 Safari, I notice it had three wires. On close inspection, two were 12v and one was ground. The two 12v wires differed in that one was highly filtered (good quality) but lower current, the other was crappy DC but higher current. Presumably the good quality circuit was for the radio/8-track player.

In some converters the 12v output is divided, one leg for battery charging, the other for trailer circuits.

Either way, to hook up your two wire converter, you need to figure out which of those three wires are for 12v and hook both of them together to the 12v output of the converter. Just be sure they are both for 12v. One of them may be the charge line from the tow vehicle, which is OK.

Zep