I have seen many posts / threads on Fusion Battery draining or parasitic draw but not any answers. What causes this if all the normal things are good like battery, alternator, lights etc.?
I have had 3 different mechanics have my car for weeks and they all gave up or didn't have any more time to put into it.
I did troubleshoot myself and pulled Fuse 36 Passive Anti-Theft Sensor (PATS) transceiver and that worked, it set for 6 days and the battery was fine only problem is the car will not start with this fuse pulled. But when I put it back in the car started no problem, before / with fuse installed it would be completely dead in a day or two?

 

This is not something you are equipped to handle. There is a problem with the security system and your best bet is a dealership that will have the INFO, Equip and training to repair.