I have a 1993 518. The other day out of the blue I went out to the car and the flashers were going off. Pulled the relay and it stopped. I then started the car and put the relay back in but know my radio, windows and wipers don't work. I went a replaced all the modules under the back seat and the fuses under the hood to no avail. After a couple of days everything started to work again but only for a short period of time then it would go back to hazards flashing, windows, locks, wipers and radio not working. Anyone have any ideas? I also replace the alarm hood switch, did not change anything.
Alarm Problem 
Linear Mode
