Fuse Blows on Bedroom Light Circuit

Had a similar issue with an 05 Cardinal. I traced wires, tightened connections, secured connections in tbe 12 volt panel. This went on for a few years with me buying 15 amp 12v fuses in bulk. Then one evening I went out to get something out of the street side bay and my wife said the lights just flickered when I opened the bay door. I closed it and opened if again and the bedroom lights flickered. I was watching the cargo door as I lifted it and the door touched the underside of the bedroom slide and sparked at the point the two metal trims touched. It blew the fuse that time. I could nevet find the ground point that caused the short but I put a strip of black elec tape at tbe point of the spark and never blew another fuse up to the day I sold the fifth wheel. And yes, I told the new owners about it and left the dozen or more 15 amp fuses with them..