Go to this thread, because @jplace1011 had similar issues with his for the last few weeks, and we all spent a bunch of time going through all of the tests you need to do to track down the power issue.
Lots of good tests. I even put a video out there on how to test things with a multimeter.
Here We Go Again Low Voltage M1009
I feel like I’m just running around in circles here with my M1009! When I picked up my vehicle, to fix an oil leak, the mechanic said he had to charge the two batteries overnight. All because it won’t start. I decided to test the batteries today and here’s what I got: Off Front 12.53 Rear...
steelsoldiers.com
Lots of good tests. I even put a video out there on how to test things with a multimeter.