Your search for "trailer wiring harness" revealed the following:
Which Brake Controller Wiring Harness Fits My Truck?
You have the trailer. You have the brake controller. Now you need to connect the controller to the tow vehicle without turning the dashboard into a wiring project. On many trucks and SUVs equipped with factory tow wiring, the cleanest solution is a vehicle-specific brake controller harness. The challenge is...
Repair the Wire or Rewire the Trailer? How to Know When You’re Done Patching
One bad trailer connection does not automatically mean the trailer needs to be rewired. But there is also a point where replacing another corroded connector, twisting together another broken wire, or chasing another intermittent light stops being a repair strategy. The question is not “Can this wire be patched?” The...