multi issues please help

I have a 04 xterra and just recently the rear defroster has been turning on and the set light on the cruise starts blinking till you turn on the rear defroster. Now it seems to have hit the rear wiper blade, goes on and off by its self. turning on the defroster stops the rear wiper. turning off the engine gives us the oil, battery cluster of lights on the dash till we turn off the defroster. Any ideas would be helpfull my mechanic friend is puzzled too.