Bob Landry wrote:
Really?? I think that everyone here is bright enough to figure out that the cover of the truck's plug latches the 7-way plug in place and that if the plug is not seated properly the cover doesn't latch.
The OP implies that he was not aware that the door was a latch. Go back and read for yourself.
If the spring on the door is good and it's latched, it's IMPOSSIBLE for the plug to come unplugged without breaking something.
Even if the plug was yanked because the cord was too short... It would break the door or yank the wires out of the plug. Surely the OP would have noticed either of those things.
I only mentioned it because I have made that mistake myself when I was in a hurry. Luckily the plug did not come unplugged on the road, and everything worked fine, but I noticed it wasn't latched when I got to my destination.