Trailer light problem

I went to hook up my truck (2016 Pete 389) to the trailer this morning and the trailer lights came on for about a second... then went out.
I checked all fuses and all checked out good with test light. Even changed a couple to be sure. Still nothing.
I put a cord tester on the end and the red light at the top comes on and a couple green light on each side of the tester under the red light.
If I turn my hazards on...two green lights blink and the other two green lights (that were on solid before hitting hazard switch) are also blinking.
So there is power coming through the cord to some extent...but nothing on the trailer. I tried hooking to another trailer and still nothing so it's def a truck issue.
Changed power cord with a spare I had in the shop...same thing.
Not sure where else to check....pigtail going up to cord maybe?

 

I pulled the cord off and plugged the tester in where the trailer cord plugs I and it was the same.
Im thinking maybe a short in the pigtail...

 

Yeah I'm going to have to check that next. Can't see what else it could be beside maybe chassis node?

 

I checked the fuses under the hood and in the cab