have an 89 xjs v12 car runs and drives great when its running for no apparent reason that i can find the car will just shut down while driving or parked , it doesn't seem to give any warning as to when it's going to happen. it's very odd when it happens because one time it will shut down and everything will work, except spark, the next time it will shut down and the starter wont work or the windows wont operate or the stereo wont work but i'll have power to the coil please if someone has experienced this let me know how to fix or what direction to go in thanks

 

thanks will tryhope it works