HELP! JUST DONE A VIRGIN SAT NAV FIT ON AN E39 M5. PROBLEM IS I'VE NO STEREO NOW.THE NAV AND OBD ALL COME UP ON THE MONITOR, BUT THE RADIO MODULE DIDN'T SEEM TO WORK. SWAPPED ONE OUT, STILL THE SAME,NO POWER TO MONITOR TO TURN UNIT ON,IE NO LIGHT WHEN TURNING L/H KNOB.CAN ANYONE HELP ME?