willydimes

Hey so Im in the middle of a Side Assist retro fit and Ive got wiring diagram but I am a bit confused when it mentions a splice at connection X in the main wiring harness. I dont understand what that means because if I am wiring from say a Data Bus module to a switch I dont get why I would need to splice in the middle of it if the wire doesnt even exist in the first place. Here are the diagrams, I just want to understand them all before I start wiring up the car so I have as few surprises as possible.
If anyone can help I would greatly appreciate it.

The last 4 pictures are actually 2 sets as the person who sent me the pics couldnt get full page in one. I also have an 08 so for pictures 2,3 I am using the left side of the diagram as my diagram.