Has it ever worked or have you bought it with these faults? Underbonnet fuseboxes burn out and as there are a number of different ones it's possible that the fusebox is failing or it has already failed and someone has replaced it with the wrong one.
Thanks Richard for the reply in fact bought that RR with loads of problem but resolved it one by one but that fault with the window wipper and a/C been there since I had it but no one was able to clear it. When I reset the bcem it does work once in a while. I even changed the bcem engine unit and it worked fine until the new bcem got hard bricked and won't get out of immobilized state even with key fob so I had to go back to my old bcem to run the car.