I bought a trailer harness for my 2015 Nissan frontier, one that has the inline 4 and the 7 round. I hooked up to trailer and lights werent working. I bought a new trailer light kit since old one was rusted and ancient. Then I thought hmmm what if its the plug on the truck? I put the circuit tester to it and it isnt lighting up. It should right??? Truck was running when I tested it. Theres 2 plugs under the bumper it hooks up to so it should work just fine. Assuming the factory wired it properly in the production line. Am I missing something? I did look at a couple fuses trailer related they looked fine unless I missed one