I also have a couple of devices I have written about in previous threads on this forum which I can use to test the pedestal outlet before I plug in to not only check for polarity but for correct voltage. I have been known to roam from site to site in RV parks in Mexico looking for a properly wired pedestal - I have also been known to rewire pedestals myself. I also have a pigtail dogbone thingy I made up that reverses polarity so if only reverse is available and I don't want to mess with it I just plug in my reverser and all is well. Many other tricks developed over years of travel in Mexico and messing around with their electricity.