Voltage regulator problem with 1968 Dart

^^Your questions seem off track here^^. What have you checked in the alternator / field circuit. So far as the main splice, it is illustrated very well by the MAD electrical article

Catalog

Catalog

amp-ga18.jpg

The splice is up under the dash a few inches from the ammeter in the big black ammeter wire. Power comes from the starter relay big stud---fuse link--through firewall--to and through ammeter--to welded splice. From there it branches off NOTE that there is NO fuse protection except for the main fuse link, and that is poor protection. I got to witness an entire underhood harness smoke in the early 70's because of a diode that fell down inside the alternator, and THEN the link blew

Nothing in the power feed TO the VR should hurt it. It is most likely on the LOAD side of the VR which is the alternator field and that circuit. And be sure the VR is GROUNDED

The power path to the alternator field is ignition switch---through the firewall--to whatever splice is in the dark blue "ignition run." This varies by year. From there, the dark blue feeds ignition "run", the VR power, electric choke if used, and any smog devices under the hood. None of that could smoke the VR. It is a power feed You CAN however, smoke IT, because the "run" line is NOT fused other than the main fuse link, and that is darn poor protection.

I tell you again. Check the field to alternator case for resistance, check the green wire for shorts, and check the VR for being grounded.