2012 Tahoe Ltz electrical gremlin

[Roosters_Hoe]

Got this Tahoe a few months back and having very weird issues lately.
Remote start worked when I got it but would not shut off when removing the key or anything I swapped some relays. Now the remote start quit fine I moved on.
Now the back hatch won’t open vehicle randomly drags starter I’m talking a week or two intermission, drives great never shuts off or anything for hours,
now I can turn the ignition off take the key out it will stay running until I open drivers door. Also while running hit the unlock on the fob the entire dash gauges etc shuts off vehicle still running. Turn it off with key door open starts right back up no issues. Should I start by replacing every fuse and relay? Is there a module I should start with?

 

[Doubeleive]

Got this Tahoe a few months back and having very weird issues lately.
Remote start worked when I got it but would not shut off when removing the key or anything I swapped some relays. Now the remote start quit fine I moved on.
Now the back hatch won’t open vehicle randomly drags starter I’m talking a week or two intermission, drives great never shuts off or anything for hours,
now I can turn the ignition off take the key out it will stay running until I open drivers door. Also while running hit the unlock on the fob the entire dash gauges etc shuts off vehicle still running. Turn it off with key door open starts right back up no issues. Should I start by replacing every fuse and relay? Is there a module I should start with?

first place to start is the battery and battery cables, grounds.
take them all off, wire brush, reconnect EVEN if the LOOK fine.
other things you can do is ohm test the battery cables they have been known to corrode from the inside.
remove and reseat the fuse box, while the top is off clean any visible corrosion