New alternator, not charging

OK I missed that.

You can do some intelligent guessing. Jumper the two wires that connect to the VR together. This will put "full battery" onto the field from the blue IGN wire. Start, run, see if it charges and it will OVER charge if you rev it up. If it does that---tells you the alternator and field wiring--and the charge wire path--are all OK, and that likely you need a VR. Make CERTAIN the VR is grounded