It's the crank sensor!
Join Date: Nov 2007
Location: Central Minnesota
It is NOT that unusual to see a new(er) radiator fail. I've seen it quite a few times.
Of course, a comprehensive inspection is warranted. With the BEST light you can get your hands on. Leaks can be very difficult to find oftentimes. Search both engine bay and from underneath. Get it on ramps or a hoist if you can't find it.
99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!