More Charging Issues

I have 912ULS on a Zenith Cruzer that is 5 years old and 450+ Hrs.  EarthX ETV680C battery.

 Charles had a 5/29/19 post in this forum about a charging issue problem. He swapped out the voltage regulator with a new one and solved the issue. 

About two weeks ago my amp readings started to bounce around from - 2A to + 8A. Previously, the normal was zero amp reading and 13.9 battery voltage.  The -2A is the normal when engine not running.

Most recently, on a one-hour flight, it was a steady -2A with a slow battery voltage drop. I'm thinking a voltage regulator issue.

Any other ideas?

Jay