Wiring fault message on Ford superduty trucks

[Slufoot733]

Just a note of information for anyone who may encounter this issue. Recently I began receiving a "Wiring fault on trailer" message on my 2008 F-350 diesel. BUT, I had no trailer connected at the time. When I did have the trailer connected everything was fine. I got the message every time I stopped on the brake or used the right turn signal but ONLY when no trailer was connected. I recalled reading here on MOC about a similar issue being caused by water in the 7-pin plug under the rear bumper. So I immediately checked the connector and sure enough, there was a small amount water inside the plug. Ford packed the plug with a bluish color grease but there was a small void and the water found it. I simply blew out the water. I then placed a nice thick bead of grease around the surface of the connector where it joined the wiring harness and snapped it back together. Problem fixed! .......at least for now. Now if I had taken the truck to the dealer they would have run a computer diagnostic and spent at least a hour or more to fix this (if they even fix it the first time). THANK YOU MEMBERS OF MOC for providing good solid advice based on your experiences. This repair cost me $0.00 and about 40 minutes time.

[stiles watson]

Yup, had water in my 2008 F350, but it was due to poor installation by the Ford dealer. Another Ford dealer repaired and sealed the wiring. Did not have another problem as long as I owned it. Good work on your part.