Update:
Back in business. Problem solved. Found a broken wire on the Main relay coil going to the ECU. Spliced in a new wire all is good. Thanks, alexpops for your help pointing out the grounding issue. It stirred the old brain cells to check the grounding system.
I have a 2021 MT347 Cab tractor with 1500 hours. Shut down in the afternoon after cutting hay. Tried to start up after a few days and all accessories came on but no start. Console indication of 0.0 Volts as in picture attached. I have checked every fuse I can find by removing and testing with...