flickering lights 66 dart

I too would check all grounds but in addition check the connectors at the firewall and/or get rid of them by crimping and soldering the pass-thru wires. You really only need to do the big fat red one (going to the ammeter) and fat black one coming from the ammeter and going back to the alternator. Also check all your wires at the regulator for good connections. FYI, the newer alternators have only one field winding, not two but they do have 2 terminals because neither of them are internally grounded.