I have the same exact problem with my 2014 Fusion Energi Titanium with the trunk area fan noise after shutting it off and a dead battery a few hours later, even after replacing it 2x.
Does anyone know if the above suggestions actually solved the problem for them, or was a dealership/electrical shop and lots of $$$$ needed to fix it?
I looked in the Trunk/Battery area and the cables are not near any metal tabs.
They and show no signs of chaffing through the insulation like in the photos above.
I decided to re-wrap them in thick electrical tape just to be sure, but still no luck.
When I have the codes read, they say nothing is wrong.
It's nerve racking to never know if the car is going to allow us to start it after it sits for a few hours.
Sometimes we are not near a place where we can plug in the battery tender so we know it will start.
Like today, my wife got stuck in the rain after Church because the 12V battery was dead after less than 2 hours.
It's a brand new battery, less than a month old and was fully charged when we had it installed.