Voltage problems, cutting out when hot

mopower76 said
The 5.90 and the 10.19 volt are measurements taken from either side of the MSD .8ohm ballast with the key in the on position, engine not running.
The two pictures that follow are being taken from the 5.0ohm side of the factory 4 pin ballast in the same manner, key on engine off.
And yes, one of my main concerns is in fact why (or where/what) is the VR getting the wrong information...
Thank you for the well laid out explanation and graphs.

What do you have from the key switch? Functional path is power to ignition switch---out of the switch on "ign1" (ignition run)---through the bulkhead connector,---and to one side of the ballast. If you can't find that wire, disconnect at least 3 of the ballast wires and look for the only one which has power. Note that, hook everything back up, and measure that point---key in run--engine stopped