Look at the wire coming from the stator to the regulator. See if there are any breaks in the wire where it may be shorting on the frame. Your volt meter pegging says a direct short.

 

I have had excellent service form a Cycle Electric voltage regulator on an otherwise stock machine. Slightly less expensive than the Harley unit also, once your warranty is gone.

 

My 12 Heritage had 2 voltage reg failures, the first one just before the 2012 recall but after that it was in and out of the dealerships for multiple electrical problems and poor running.

I had enough of it and traded it in 7 months ago. I once asked the service manager for a print out of the warranty work and it ran to 5 pages.