Exhausted, find out the type of failure that it is. If it is a coolant leak, that's one thing; however, it could be a contactor issue like I recently had and that is fixable with relatively little cost and effort.
Dealers will stop at the boundary of the battery when diagnosing. If it is anything inside...even if it would take 10 minutes or $0.10, they don't know and will send it to Ford. My dealer quoted me $14,000 for a replacement. But Forscan and Dealer gave a code for stuck positive contactor....AND...it was a stuck positive contactor. I bought a new contactor on eBay for $140 and did it myself. I also bought safety equipment and insulated tools, but after that, I was somewhat comfortable with doing the work.
I fixed it back in October and it has been working perfectly...but that is my experience; your mileage may vary.
But best of luck with whatever you do.