When you say follow under carpet, what do you mean? Like take the carpet out?? How do I follow it???? What do I need to take out to access the harness directly?

This is a good point because i had a problem about a month ago with my carpet being wet on the passenger side. This very possibly could be my issue

So i pulled the carpet up on the rear, very damp. None of the cords appeared corroded though. I cant seem to figure out how to access the harness going up behind the rear seat. I removed the cushion part but cant figure out how to get the end parts of the back down. Its almost like they are stuck. The seat folds down but the ends are stuck up (the part where the wire run behinds I believe). Any suggestions moving forward? How do I access the harness going up the seat. I am going to test the wires that we in the wet area tomorrow as well

update: Tested wires going to amp. There is power going to it (the orange wire). How would I go about making sure there is power coming back out though?