4-Wire Lucas Alternator Question?

[baws]

I was gifted an alternator recently and it has a connection for a 4th wire. In the midst of time and my memory, my '73 had wiring for this version of the 18ACR unit.
Am guessing I can just retrofit/wire this part.
Please correct me if I am wrong.

[tr6harris]

Looks plug and play to me.

Some alternators are internally wired so as not to need that excitation wire.

Connecting it shouldn't be an issue either way.

[TuffTR250]

Have you looked at the Dan Masters Triumph TR250-TR6 Electrical Maintenance Handbook. I've had the hardcopy book for many years. He recently posted it on line. It is an excellent reference. I'm not sure it will cover your questions but it is worth a try. Here is the url for the on-line version: http://www.advanceautowire.com/tr2506/
Bob

[46er]

Chapter 30 in the above Masters manual may help.

http://www.advanceautowire.com/tr2506/Chapter%2030%20-%20Alternator%20Upgrades.pdf