I just recently found a leak in the rear corner of my fiver. Started with mildewed carpet, wet vinyl, got that out, found wet, rotten wood. This was inside a closed cabinet, so was not readily seen. Checked outside, appeared water coming in from around vinyl trim about 1/3 way up from the bottom and also around the outlet for the cable/phone line. Cleaned and sealed both places.
Then, found the shore power plug had a bad, burnt spot along with the same area on the trailer receptacle. So, more than likely was all related. Fixed leak myself along with water damage but had fiver to CW for electrical repair. All is well.
