Here is a diagram of the Autolite charging system (mechanical relay) as found on the Pantera. Note that it is not Pantera specific, as the wire colors are different, but it is a good visual aid.
Note that voltage is available all of the time at the "A+" terminal of the voltage regulator and at one of the normally open contacts inside the regulator, but no voltage is present in any other part of the voltage regulator or the field of the alternator until the ignition switch is turned on.
John
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