Three problems related to wiring have been reported for the 2004 BMW 530. The most recently reported issues are listed below.
Nearly every BMW suffers from failed wiring in the headlights. This should be addressed as a recalled oint of failure as it involves everybody on the road.
The wiring inside the headlights are all crumbling and exposing the copper within creating an electroncal fire or shorting of the system. This appears to be very common on the e60 series BMW and should be addressed.
The headlight assembly produced by hella contains apparently defective wiring. The insulation on the electrical wires to the high beam bulbs and the parking light bulbs deteriorates and crumbles off leaving exposed electrical wires in the headlight assembly. Moving the wires during removal and replacement of bulbs caused the insulation to break off completely. The problem was just discovered, but was obviously in a state of decay for a long period of time.