Alternator wiring

[Aardvark]

Hello chums
I'm ready to pop the engine back into the crossover. I've fitted an alternator conversion and looking on the internet found the wiring diagrams. It seems all very simple. The 3 red wires are joined and the green and blue are joined for the dash light. However my regulator has another small wire going onto one of the red terminals. Can anyone tell me what it's for and what to do with it. I can't find any info on it and it looks factory, not add-on.
Cheers dears
Aardvark

 

[67panel]

If you have a diagnostic socket it goes to that.

 

[Aardvark]

I see. So do I just splice it together with the 3 red cables?
Aardvark

 

[gagvanman]

If you don't have a diagnostic socket this should help: