Since you disconnected the VR and it stopped charging, this indicates the VR circuit is not faulty. Next is to determine "is it a bad VR?" or "is it voltage drop?"
To find out.......First go to MyMopar and look around, download a service manual and the aftermarket wiring diagram, both free
MyMopar - Mopar Forums & Information - MyMopar Tools/Reference
Next Understand that the "ignition run" voltage coming from the switch (as well as the ground circuit) are what might be the culprits here
The circuit "in general" is battery..........starter relay.......fuse link.........through the bulkhead connector.........to ammeter circuit.........to welded splice in the under-dash harness..........to ignition switch connector.........through the connector........through the switch.........back OUT the switch connector on the IGN1 "run" wire (usually blue).........back out through the bulkhead connector and into the engine bay
Out in the bay, that wire branches off and feeds several circuits, by the way NONE of which are fused. "Generally" feeds
ignition system
Voltage regulator
Alternator field (light blue)
electric choke if equipped
some smog du dads on some cars
NOW find one of these the best is the "high" (key) side of the ignition ballast. Turn the key to "run" engine off. Probe your meter on the ballast and find the HIGHEST reading
Leave that probe on that terminal, and move your GROUND test probe to the battery POSITIVE.
NOW you will read a very LOW reading, the lower the better. Zero would be perfect. More than .3 tenths (three tenths of one volt) needs investigation. This higher voltage (mine was 1.5) ADDS VOLTAGE to the VR setting. That is, in my case, the harness drop was 1.5, and assuming the VR was properly set at about 14, this means the battery WAS CHARGING at 15.5 volts!!!
If you do NOT read more than .3 then the harness/ switch/ connections is OK
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Remove the VR, scrape around the bolt holes on the rear of the VR, scrape around the firewall, and remount tight, using star lock washers, and retest for charging voltage.
If the above does not change anything, try a new VR