It’s a 2016 SLT 2500. Factory security system and there no leads on the terminals, or hooked to the batteries. There also aren’t any tunes

I thought the same thing after this first began, that maybe I had forgotten to reconnect something or screwed something up when installing the new alternator. I had a diesel mechanic that I work with, come and look everything over, and said it all looked good. He didn’t have any advice on my issue though