Hi Ron, I pretty much covered everything in posts 10 and 12. The message was "check trailer wiring", followed by "trailer connected!" My fifth wheel is a 2005 Titanium. The trailer brakes work, the lights all work, and yet I get this warning. That was Nov 2015 and March 2016. Last year Nov 2016 I drove to California and back to Canada without any problems. This Nov 2017, I drove the first day, no problem, then the 2nd day the same warning. I pulled the fuse! I will head back to Canada end of March 2018 and I am almost certain I will get the same warning and have to pull the fuse. I have had the truck to 2 GMC Dealers, St. George, Ut, and El Centro, Ca and neither can find the problem. They basically said it is in my trailer. My Titanium trailer had new axles and brakes installed in 2012 and I never had any problem with my 2009 GMC 2500. I just don't know where to look to find the problem. I am just glad I can stop the Ding, Ding, Ding, Ding by pulling the fuse to the radio. My wife and I don't mind not having a radio, so it is not really an issue. It upsets me that my truck thinks there is a problem that is not apparent otherwise. Thanks, Al.Tell us about your truck, the EXACT message you receive on the DIC, the conditions under which you get the message, and what you've done to troubleshoot.