NHTSA Complaint #11558296 — 2021 FORD F-150

When a trailer is connected the right side trailer brake light fails to operate; the lights on the truck work properly. When the trailer has been recently disconnected warnings on the dash appear saying "Blind spot and cross traffic alert deactivated trailer attached". I also get trailer left and right turn lamps fault check lamps warnings and the turn signal indicators flash at double speed. These things always clear up after a couple of days until a trailer has been connected and disconnected again. I have two different trailers and they both do the same thing. Just for the record, the right turn signal and hazard flashers on the trailer work correctly. My dealer has observed everything that I stated above but claims he is unable to get parts to fix it. The cross traffic alert malfunction and the non operative trailer brake light would appear to be safety issues. So far, no one has been involved except my dealer's service department. If I don't hook up a trailer everything has and does work correctly. I took this truck in to the dealer a couple of years ago due to the dashboard warnings but did not take my trailer with me at that time; they were unable to fix it. I was unaware at that point that I had no right trailer brake light; this is not easy to see unless someone is following me.