Bmw E34s have a big fuse right after the battery that protects the car electrical harnesses.
Failure syndromes:
• Intermittent simultaneous falure of wipers, sunroof, windows, central locking, radio...
• No power, like if the battery was dead.
525i Procedure
Tools/Parts Required:
- 10mm wrench or socket.
- New fuses.
1. Disconnect the battery.
2. Open the fusible link box.
3. Remove the 4 x 10mm screws and change the fusible links.
4. Installation is reverse of removal.
Good Luck, Mike please let me know if this is helpful.