I had one manage to put a square peg in a round hole and they say it couldn't be done. 6 years ago the guys hooked up my trailer and the new guy (who is to date the dumbest employee I have ever had) plugs the trailer into the truck we use the 7 prong style plugs on our trailers and they have a square rail on the top of the round plug so you can only put the plug in one way. He managed to jam it in upside down so my blinkers were reversed the entire day. Was a few beeps but never understood why so the day comes to an end I'm 2 towns from home its getting dark fast so as I'm going down the road I pull the light switch and nearly go through the wind shield. The brakes on the trailer instantly locked up when we turned the lights on so of course I turn them off but its getting dark so we try one more time and no doubt about it its the light switch that's doing it. So I drive home in the dark with no lights didn't dare try to figure out the problem it was getting darker by the second. So the next morning when we go over what happened that's when we find his handy work and man that had to take some effort to jam it in there like that.