Replacement of Battery Isolation Switch
BMW E38 750iL, 750iLP produced in September 1998 to October 1999.
As a result of frequent short journeys with a large number of electrical consumers switched on, an adequate charge level may not be maintained by the vehicle’s electrical system battery which can as a consequence result in the vehicle not starting.
Check the wiring at the X1806 and the part number of the battery isolation switch, if required install a retrofit wiring harness and/or replace the battery isolation switch. If the retrofit harness is installed, then the ignition starter switch also needs to be replaced.
The following Service Actions should also be carried out on all affected vehicles:
- Replacement of Vehicle Electrical System Battery on E38 M73TU Vehicles.
- Replacement of Water-cooled Generator on E38 73TU Vehicles.
- Increase of Idle Speed on E38 M73TU Vehicles.