You need to tell us what the 2 fuses you changed were for, besides the levels and camera. It's unlikely that an external backup camera took in water to the point of blowing a fuse. Possible but not likely the cause- I'd focus my energy elsewhere.
Also try a mobile rv mechanic. I use and post reviews at http://www.rvservicereviews.com/
PartyOf5 appreciating our Creator thru the created. 5 yrsL 50k, 49 states & 9 provinces.
May you find Peace in all you endeavor.