oh wow, I posted this in another thread. Had a similar issue and it turned out to be a connector under the center console near or in front of the cup holders. Loose pin and or bad connection. Hope this helps anyone with a similar issue.
I have a 2015 250 AWD. I had an issue with no audio. No loss of power to the head unit. It seemed to come back then went out again. I thought it might be the amp but that wasn't the case. The dealer was able to find that the issue was with a connector under the center console near or in front of the cup holder. They said they adjusted the pin and re-seated the connector and the issue was resolved. Haven't had a problem since. Hope this helps anyone having a similar issue.