2014 GMC Sierra 1500 battery light comes on when truck is off

Battery light comes on when truck is off. All lights will come on when I park in my garage after I turn it off Randomly for 3 to 10 minutes

Sounds like a bad BCM or body control module. That is the computer that deals with all those things.

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Could it be a bad ignition switch intermittently shorting to the run position?

I wonder if there is a bad diode in the alternator that lets the current from the battery flow when it should be blocked. I remember seeing this happen on a 1962 Oldsmobile. Back in those days we didn’t have Body Control Modules, so I may be off the track here

You would have to think that the alternator has something to do with the issue at least @Triedaq. The alternator is on the return side of the warning light circuit so something on the power side would have to allow current to flow in the opposite direction of the normal flow and get to ground somehow for that to happen. It seems to me that it is more likely power is somehow getting past the ignition switch and turning on the light. There may be a faulty module that is causing this to happen.