1968 Dodge Dart V8 Two Wheel Drive Automatic 196000 miles
The battery does not charge, it is about 4 years old. The reading is 12.28 V. The voltage regulator used to have bad terminal contact, but after each cleaning it used to work, until now. The voltage on the alternator terminals with the engine running (started with quick start battery) is fluctuating between about 4 to 7 V, depending on throttle speed.
The car runs fine once started.
Which component is faulty? How can I measure to be sure?