Check the lights. They may have individual switches on them that are turned off. I am assuming that they all work on a single switch.
Under the coach you will find a junction box at one end or the other of the slide. Romex 120 volt wire and 12 volt wire will come to 2 different j-boxes. Coming out of theses boxes will be rubber cord to feed the slide and allow for flexibility. Remove the covers and check the voltage.
As for the water it would be a leak from under the sink. Not from the holding tank. Water does not leak up thru the floor.
