Reverse polarity?


I have a 2019 Mallard M312. While staying at a state park this weekend (30amp), my surge protector was reading reverse polarity when the AC kicked on. I replaced the 50 amp-30 amp dog bone and still had the issue. I swapped out my cord, surge protector and dog bone with my buddy at the next site. His electrical set-up was identical to mine and showed reverse polarity when hooked to my camper. My set-up was fine on his camper, leading me to think the issue was with my camper. We were able to switch sites and had the same issue. Any guesses what it might be? Everything seems to work in the camper, including the AC with the reverse polarity light lit.


Well-known member
I think you need to get an AC volts multimeter, and measure the entire shorepower feed system logically starting from the park power pedestal ending at interior electrical outlets. Forget all previous tests as they can confuse things.