I wanted to add to this thread as it helped my wife and I figure out what the god awful sound was in our new 2017 Explorer Limited. Yes, that's right, same problem in a Limited trim, we don't have the sport trim. What we do have is the 2.3L Ecoboost in our Limited trim.
Our dealer continued to tell us that it was "normal operation of the vehicle". Even though the tech could hear the sound the dealer insisted it was "normal operation". Obviously I was not pleased so I set out to prove them wrong. Thanks to this thread, I was able to do just that.
I took the vehicle up to the dealership and showed them that by removing the fuse the sound went away. This led to them making a phone call to Ford and they came back to me saying the issue is in diagnosis stage but there are people at Ford "aware" of the issue. No certain part of fix has been figured out yet. They did however mention that a new ac/dc power inverter would be ordered and they would call me to let me know when it was in. They said it was "backordered" ???
Honestly, I don't think they have any idea what to do, they don't want to say it though. I told them I would be calling every few weeks and that if this goes on for too long I'll be getting Ford involved, not sure what else to do. Sure removing the fuse fixes the issue of the sound but it creates another issue, my kids can't use the plug in the back for our road trips, once of which comes at the end of this month as we do a 16 hour drive to South Dakota.
I'll make sure to update this thread with any new information I figure out. I'm pretty persistent, probably to the point that when they have me on the phone they want nothing more than to get off the phone.
