[ipswich318ti]

The following info is from the bmw wiring diagram...
Fuse 24 (10A) connects to pin 26 on the pdc box.
pin 23 and pin 10 are for diagnostics on the pdc box (I guess you can ignore these)
14 and 18 go to ground.
21 goes to the GONG (BL/GR blue/grey wire)
pin 6 on the box BL/GE (blue/yellow) goes to the reversing lights

i picked the power, ground and reverse lights connections off the rear lights, and then install a new GONG in the front of the car where the obc gong goes,
PS the gong needs power and ground to function, along with the trigger wire (mentioned above)