im new to this forum so firstly hello all.
i have a late 1999 e39 touring, from the factory it had the small tv screen, telephone, but no sat nav. i have managed to get hold of a widescreen monitor, digital tv module, and a mk4 dvd sat nav.
looking it the boot area where the cd changer lives, i have a single white connection plug, as per picture

connected to this is the white plug from the nav loom i bought from bmw.
this loom i bought,also has a black plug

i have searched the loom in the car for the black plug that this new loom plug connects to, but its not there.
the new loom has a burgundy and a blue multi plugs which go into the back of the loom, an earth strap which i have put to earth, and a white multiplug which i think goes to the vacant white plug on the digital tv module.
so all are connected except the black plug in 2nd picture.
if i turn the sat nav on it seems to work picture and location wise,
my first issue is i have no sound from the sat nav(radio and tv have sound,and radio mutes for the voice instructions but dont get voice)
anyone know what i need to check,as this is a genuine bmw loom.
next question is i have also read in another thread in this forum,i need to tap into a speed sensor, and reverse light. my thoughts are that the black plug are for the speed sensor and reverse sensor wires as there are only 3 wires and one of those is an earth.
i have park distance control and self leveling suspension,and if i remeber correctly,i can take the speed sensor from one of these, can anyone say which wire from these unit carries the signal and to what wire i connect to on the new loom, if it is one of the wires on this spare black plug,then the other must be the reverse sensor wire? and the brown earth wire i just run to earth or must it be an eart on one of the modules i tap into.
i havent driven the car since starting the install (waiting for new tyre ordered in) so cant tell at the minute how it works on the move.
i have tried to access the WDS that has been linked in other threads, but my pc will not allow the attachment to be loaded,and i dont know enough about windows to do this safely.
any help or guidance would be appreciated as i am pulling my hair out.
im so close to acheiving it fully working its just this last hurdle seems to be very high