shut off

Good morning all, I come in hopes that you all can assist me with my 04. I'm new to KJ world. I bought one over the winter for mainly a get around vehicle. I am having TWO major intermittent issues that keep happening and are getting worse with everyday. And I do not have a single code...

So running my 05 KJ the other day (200k on body/100k on engine) up a serious mountain in my area (3,200 ft) and quite step slope about 3or4 miles, my cruise set on 70mph, a/c running wide open bc it was 90some degrees and humid as all get out, stereo pounding and signing along and she just shuts...