There are several possible causes, the wiper motor has died, the rear wiper relay has failed, the combination switch for the wipers, the contacts on the bottom of the tailgate are dirty/corroded, or the earthing through the tailgate hinges is bad (common fault) it wont be a fuse problem as the front wipers and the washer jets are on the same fuse and you have'nt said they are not working
nigel, September 2010