I used a cover from a storage container to make a cover for the fridge vent. I attached it with 10 lb. velcro tape. this should keep the rain water and splashing water from trucks passing from coming in. It must be removed before turning fridge on . I have not tested it in the rain yet
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I had a similar problem with my 13 Scamp. In the owners manual pack-it there is a gasket that goes on the frig vent door. Once installed no more water leakage. I hope this works for you.