Help Running New Wire To Alternator For Cluster

[1972BlueC20]

Hi Guys,

I am about to do the idiot light to full cluster conversion.

There are still a few things I am still not 100% on, I'll ask 1 and a time...

1) The new wire that I need to add to the # 1 position that will go to the alternator....do I just solder it to the area that I drew the arrow pointing to?

This pic isn't of my truck, I found it on the forum. Assuming mine will look something like this once I dig in.

18 gauge red wire good??