I take it you mean the fuse box in the engine compartment at the firewall on the driver's side? Please excuse my ignorance, but only getting home twice a year I don't spend much time with this car. If there is more than one fuse box please point me in the right direction.
For information, the replacement relay I have is: 89 5120 0000
Is there anything further on the shorted door light idea?
WRT the airbag: thanks for the heads-up (guess MB was ahead of BMW on passenger safety when my 535 was made). I was planning on disconnecting the battery before embarking on this project. Thanks, Will