I have had three different water leaks in my R.V.
1. The first one was in back of my water heater where the cool water enter the heater.
2. The second one was in back of my toilet where the spray hose connected to the toilet.
3. The thired one was under the sink in the Bath Room just where the water hose connected to the faucet under the clamp the line had a crack in it.
I turned off all the incoming water and the water pump then after I dryed the area I laid down white towels and then turned the water on again.
It didnot take to long to fine out where it was coming from.
Just a thought.