It could be wiring issue. Here is the link you can refer for your stereo problem. Hopefully it can help.
https://www.lifewire.com/car-stereo-only-works-sometimes-4036329
You can refer this link for your reference. Hopefully it can help you. Good luck
https://www.jk-forum.com/forums/jk-write-ups-39/transmission-cooler-37839/
not sure if that is what you need or not, just give for your reference. hopefully it can help you
https://www.yourmechanic.com/article/how-to-open-your-car-hood-by-joyce-morse
https://www.jlwranglerforums.com/forum/threads/block-heater-cord-found-it.4331/
Review this article for your reference. Hopefully it can help you to figure out the issue and solution.
https://www.2carpros.com/articles/vehicle-bubbling-noise
Have you tried to check the transmission fluid. Maybe you truck refused to get gear due to low or leaking transmission fluid. Anther cause is possible failing speed sensor. Just take a look at these things.