[Quad T]

I have had several erratic lights not working issues, and each and every stinking time it comes back to a bad connesction between the trailer's pigtail and the Titan's trailer plug. Sometimes it has been the Nissan male socket and others the trailer's female plug. I now just make a habit of cleaning them both with a quick spritz of brake cleaner and a wire brush for the male and a pocket knife scrape on the female.

With luck something that simple will tturn out to be your problem, I know in my case, each and every time it boiled down to a dirty connection.