Today I attempted to find the short in the HV cable for the X2-8 BT ion pump (before proceeding with cutting off the extra cable length-unrelated task) as follows: 

I cut off the connector at the controller end and left the pump end connected to the pump.  I then connected the "Megger" (5000VDC @ 12mA) to the controller end of the cable and demonstrated that the short was still present.  I visually inspected the 100'+ excess cable for any obvious nicks or cuts (I did note one feature that looked like a clean incision or sharp slice).  I disconnected the pump end connector from the pump and let it hang in space -> No change.  Cable still shorted.  Finally, I cut-off the connector at the pump end and separated the conductors -> No change.  Cable short still present.  

Tomorrow I'll double check/inspect the run of cable that is in the HV raceway in the VEA and then proceed with cutting of the 100' extra cable length which will eliminate the incision "feature" previously noted and which I was going to do anyway prior to the appearance of the short.