if the water tank has been removed just plug the line and tape the wires for the pump and the rest of the plumbing should be ok, plumbing should be pex pipe, the ceiling lights should be 12 volt dc, black wire= battery positive, white wire battery negative, the wall plugs will be 115 volts ac, black=hot, white= neutral, bare or green = ground. if you don't have any electrical experience anyone with basic electrical knowledge would be a big help. or you could post some pictures and I will be glad to help.