So here I was, driving down a two-lane highway fifty miles from the nearest town, no cell phone coverage, and temperatures in triple digits. An ominous message appears on the dash of our 2020 Ford F-250 Super Duty:
WARNING: TRAILER WIRING FAULT
I pull off the roadway onto the shoulder that is a mix of sand and gravel. Turn off the ignition key. Walking to the back of the truck, I see the trailer wiring connector to the truck is in place. I disconnect it and then plug it back in, making sure it is completed seated and secure. Back in the truck I start the engine and watch the dash as the truck comes to life again:
WARNING: TRAILER WIRING FAULT
These are the steps I took to diagnose the problem, do a quick temporary fix, and then a permanent repair once we got back home.