BMW Model Electrical System Failure

Vehicles involved: BMW 1 Series Two-Door Hatchback (E81), BMW 1 Series Two-Door Sedan (E82), BMW X1 (E84), BMW 1 Series Four-Door (E87), BMW 1 Series Soft Top Convertible (E88), BMW Z4 (E89), BMW 3 Series Sedan (E90), BMW 3 Series Touring (E91), BMW 3 Series Two-Door (E92) and BMW 3 Series Convertible (E93).
Fault content: The electrical system of the above vehicles failed and the vehicle could not be started.
Fault cause: Battery The positive lead of the battery contacts the conductive parts in the power distribution box.
Repair method: When the above models cannot start, first check the battery voltage. If it can be confirmed that the failure to start is not caused by low battery voltage, perform the following work.
(1) Remove the power distribution box according to the repair instructions.
(2) Check whether there is discoloration or burn marks in the installation area of ​​the positive lead of the battery on the power distribution box.
(3) If there is discoloration or burn marks in this installation location, adjacent wiring harness and nearby locations, a new power distribution box and positive lead of the battery must be replaced.