Disco 2 Engine won’t turn over, electrical issue?

Hi, I’ve recently bought a 1999 Disco TD5 auto. It ran perfectly for a week and was in use everyday. First the indicators stopped working, then 1/2 hour later the front electric windows stopped working. At that time I also noticed that whilst the vehicle was driving perfectly, the lights on the dash were showing the vehicle was in park. Got the vehicle home & checked all fuses, a 30 amp fuse had gone (apparently operating the engine cooling fan) all other fuses were correct. After replacing the fuse the vehicle now completely fails to turn over. Called out the RAC who couldn’t find the problem. A garage has now run it through a diagnostic check & it shows the car is in 4th gear. After a few days of him fiddling with the vehicle it then repeatedly started again for one day but has failed to turn over since. It is now showing its in 4th gear again. Does this sound like the Automatic Transmission ECU or does anyone have any ideas? The Garage has changed some switch on the side of the gearbox but it’s made no difference. Doesn’t know whether all of the problems are connected or a number of individual ones! Many thanks in advance!

Hi, as the symptom started and evolved seems very like BCU failure and this is not plug and play, it needs complex programming with dedicated tester