Left turn signal issue

so I have been looking around and haven't managed to find anything yet. I've got an 02 v6 4x4 and it does the strangest thing. When I'm going down the highway and change lanes and put on my left turn signal it will actually downshift. If I leave the signal on it will actually want to up shift but never does. Also if I have the cruise control on and left signal it will actually kick off the cruise control like I tapped the brakes.

I am assuming it's probably something with body module but I'm not certain

 

I didn't have that issue but had a left blinker that would blink faster when I hit the brakes. Previous owner had a wiring harness installed and I found a short in the RIGHT rear blinker, which was working normally.

 

I did find something about making sure the reverse lights have a good ground. I'll try that and see if anything happens