1970 Chrysler 300 - No Power

If I remember, yes, everything went through the ammeter (charging gauge) on Chrysler's for many years. The replacement harness - what all did it include? Was it just underwood, was it under dash, both, etc? Is anything, wire related, still original? Do you have proper engine to body and battery to body grounds?
Can I run a parallel wire around the ammeter? Maybe just by pass it altogether or replace it.
No old wire except maybe the tail light or door wiring where Painless did not supply it. The grounds are the grounds I have had for the last 25 years or more. They are clean.