Ahh,
I see what you're saying...the wire you're speaking of should go from the regulator, through the firewall, and to the load side of the ammeter gauge. If you take out the generator, yes, that wire can be removed. However, if the wire is in good shape, you can leave it connected at the ammeter, take the end of the lead off the regulator and wire it to the #2 terminal of your Delco Alternator. (It will now be the "sense" wire for you Delco alternator)