Well, I hate to suggest this, but you may have a rodent problem.
I have a yet exactly undetermined short circuit in my kitchen slide, that I have been able to isolate the refrigerator from. The the wire junctions at the refrigerator connection terminal strip, and extends to the stove lights and fans. This short is intermittent and has happened while the rig was sitting still in storage (I tried to pre-cool the refrig for a trip and came back and found the fuse blown). The fuse hasn't blown when I remove this fan/light extention portion from the circuit.
I am relating all of this because I currently am having a mouse problem in the trailer. I suspect the mice have chewed through the wiring causing an intermittent short when they come back for another meal on the insulation, or when the wiring shakes when I travel.
I have out out the dryer sheets everywhere, then started buying 4 packs of traps, then moved all of the food from anywhere the mice seemed to get into, then stuffed the kitchen and bathroom plumbing pass through holes with steel wool. I have caught about 4 so far.
Meanwhile, I need to replace that wiring, and I am pretty certain I have to scoot the refrig out some to get at it. I have seen photos of RV wiring online with compromised insulation, on sites reporting investigations of RV fires. So mice are just more than just a gross nusance. Then there is the Hantavirus risk, too. Right now, I just keep the extended part of that circuit disconnected, and get along without the stove lights and fan.