2015 YUKON XL won't start, dead. Good battery, jump does nothing.

[15xl]

2015 Yukon XL, 5.3. Three times it has acted totally dead when I try to start. No lights, dash, nothing.
Had it jumped, did nothing. Replaced battery and it started. Second time (a month later) happened again.
Charged for a few hours and finally started. third time, wouldn't start again, dead. Was going to put seats down to get at something. When I engaged the power adjust button on the passenger front seat, all power came back and it worked fine. I touched the power adjust not thinking that all power was dead, surprise. After each of these episodes I get a message to recycle power windows.
So now, what do I do to figure this one out. don't want this to continue to happen but have no idea how to duplicate for a service center and have no idea what is not happening right????

 

[Denalitank]

Following your post to see if its an ongoing issue. Just replaced the battery in my 2017 Yukon XL Denali at around 94k. Installed a isolator on the new battery duralast gold for $213 at autozone. Connected the old battery in a dual battery system. Hooked up to a 1200 watt inverter. Just to see what I can get out of it.

 

[15xl]

Having my XL looked at next week?? Now, I've noticed, some mornings the clock is wrong or the radio is on a different channel when I start vehicle. Also, had one time the display on the dash had change the info it displays. Definitely losing power sometime while sitting then returning???? Not sure what mechanics will do, it's had
to duplicate. Apparently it's not related to temperature. Some times it happens when it operating temperature, other times I get into the vehicle, in the morning, and nothing......

 

[B-train]

I know this is always stated, but if you live in a salt area, I'd check your power and ground connections.

Have you owned it since new? Or is it a used purchase? If so, from where. Just wondering if you have some previous damage that may be finally showing up in other ways. Flood, wires chaffing, etc

Or it could just be a module flaking out.

 

[Fless]

Those are symptoms of the modules losing battery connection. That could be a bad battery (defective cell, for example), or a loose battery cable connection, rotted out battery cable, etc.

 

[15xl]

I've owned the Yukon for a number of years and live in Minnesota. Never been in a wreck, always parked in garage and installed a new battery after first episode earlier this past spring. Tend to agree with the module or board going but how to find which one???? It did sit in the garage for about 4 months prior to the first loss of power.