F250 Super duty: warningng fault on trailer Oct 02, 2010I have a 2008 F250 Super Duty. When I press the brake, the dash display warning tone sounds and it displays "WIRING FAULT ON TRAILER". I do not have a trailer attached but there is an after market wir read more Wiring fault on trailer" keeps showing up on My 2008 F250 May 13, 2008"wiring fault on trailer" keeps showing up on My 2008 F250 2WD Super Duty info screen. Exhaustive search on trailer wiring shows no defect. Any ideas where to look? Truck has had an extra plug mounted in bed, and has been checked out many times.