DIY HEMI Wiring Diagrams
I wish to heck I was younger and had more stamina, I'd darn sure tackle some of this. Only advice I can say is "buy a factory manual" (or find a download, there are a few of these on the net) which covers the factory harness/ ECM you have
It's foggy but I remember discussions that the security crap can screw you up in some vehicles
And I know---I KNOW--the factory diagrams SUCK