We had a leak during torrential rains on our last camping trip. Water was under the cabinets, puddling on the floor under the
fridge and sink. I cleaned it all up and checked all the plumbing and fridge drain (we have an icebox) and tried to trace back to where the leak might be coming from. I left dry paper towels under the cabinet hoping that would help pinpoint things as it continued to rain and it did!
Originally we thought water was coming in where the
propane lines come into the front of the camper, but it was ACTUALLY from a side marker
light, where the screw had pierced the
fiberglass and water was running down behind the marker
light directly into the cabinets out on to the floor. Water coming in runs everywhere, so it can be difficult to find. We were lucky ours didn't take us too long to discover. Good luck on finding yours!