BMW X3 (F25) Service & Repair Manual: Starter lead

• Replacing battery positive lead between starter, alternator and battery positive terminal (N52T)
• Replacing positive battery cable between starter motor, alternator and positive battery connection point (N47 D20 O1)
• Replacing positive battery cable between starter motor, alternator and positive battery connection point (N55)
• Replacing positive battery cable between starter motor, alternator and positive battery connection point (N20)
• Replacing safety battery terminal (sbk)

Replacing battery positive lead between starter, alternator and battery positive terminal (N52T)

Necessary preliminary work:

• Read out the fault memory of the DME control unit.
• Switch off ignition.
• Disconnect BATTERY EARTH LEAD .
• Remove intake plenum.

Fold back cover (1).

Release nut underneath. Remove positive battery cable from positive battery connection point.

Release battery positive lead (1) from retainers (2).

Release clamp (1).

Release clamps (2).

Unlock tab (3) in direction of arrow. Remove top part of cable holder toward the top and uncover wiring harnesses.

Unfasten nut.

Disconnect positive battery cable (2) from starter motor.

Remove protective cap (2) and release nut underneath.

Remove battery positive lead from alternator and feed out.

NOTE: Reassemble the vehicle.

Delete fault memory.

Replacing positive battery cable between starter motor, alternator and positive battery connection point (N47 D20 O1)

Necessary preliminary work:

• Read out the fault memory of the DME control unit.
• Switch off ignition.
• Disconnect BATTERY EARTH LEAD .
• Remove INTAKE FILTER HOUSING .
• Remove UNDERBODY PROTECTION

Fold back cover (1).

Release nut underneath.

Remove positive battery cable from battery positive terminal.

Release positive battery lead(1) from acoustic cover (3).

Slacken nut (1).

Disconnect positive battery cable from alternator.

Release positive battery lead from retainer (2).

Release retainers (1) and detach positive battery lead from guide.

Release nut (1) on starter motor.

Disconnect positive battery cable from starter motor.

Release positive battery cable from retainers (2).

Feed out positive battery cable and remove.

NOTE: Reassemble the vehicle.

Delete fault memory.

Replacing positive battery cable between starter motor, alternator and positive battery connection point (N55)

Necessary preliminary work:

• Read out the fault memory of the DME control unit.
• Switch off ignition.
• Disconnect BATTERY EARTH LEAD .
• REMOVE intake plenum.

Fold back cover (1).

Release nut underneath. Remove positive battery cable from battery positive terminal.

Remove protective cap (2) and release nut underneath.

Disconnect positive battery cable from alternator.

Unclip positive battery cable (1) from holder (2).

Release nut (2) on starter motor only.

Remove positive battery cable from starter motor and pull out.

NOTE: Reassemble the vehicle.

Delete fault memory.

Replacing positive battery cable between starter motor, alternator and positive battery connection point (N20)

Necessary preliminary tasks:

• Switch off ignition.
• Disconnect BATTERY NEGATIVE LEAD .
• Remove INTAKE PLENUM .
• REMOVE COVER FOR WINDSCREEN COWL PANEL .

Release screw (1).

Lever out cable clip (2).

Remove cover (3).

Fold back cover (1).

Release nut underneath. Remove positive battery cable from positive battery connection point.

Unclip positive battery cable (1) from brackets (2) at rear of engine block.

Remove protective cap (1) and release nut underneath.

Release nut (2) on starter.

Disconnect positive battery cable (3) from alternator and starter motor. Feed out positive battery cable (3) and remove.

NOTE: Reassemble the vehicle.

Delete fault memory.

Replacing safety battery terminal (sbk)

CAUTION: Observe safety regulations.

To do so, read out fault memory of airbag control unit. Note fault messages stored in memory. Rectify faults. Then clear fault memory.

Use of safety battery terminal:

• From model year 1998 in Series E38, E39, E46
• From 4/99 in E36/Z3
• in each of following new Series

The different models have different installation locations:

Battery in engine compartment

Safety battery terminal is replaced with cable up to battery positive support point.

Safety battery terminal is omitted as from 03/2002 from all E46 LHD models with 4-cylinder engines.

Battery in luggage compartment behind side trim panel

Remove side trim panel.

Follow instructions for disconnecting and connecting battery.

Disconnect and cover battery negative lead.

Release front side trim panel partly and fold forward.

Battery in luggage compartment under floor trim panel

Follow instructions for disconnecting and connecting battery.

Fold back floor trim panel (1).

Lift cover (2) on battery negative lead.

Disconnect and cover battery negative lead (3).

Release nuts (4).

Remove battery cover.

Battery in luggage compartment under spare wheel

Remove spare wheel.

Release screws.

CAUTION: Do not kink air pipes.

Set air supply system (1) to one side.

Follow instructions for disconnecting and connecting battery.

Disconnect battery negative lead.

Disconnect supply cable (1) for vehicle electrical system.

Installation: Remove faulty fuses and carry out troubleshooting.

CAUTION: Pay attention to interface.

The repair cable is always a standard length.

The heavy-current connector of the repair cable has a larger diameter than the battery positive lead.

In some Series (e.g. E46 touring), the heavy-current connector of the repair cable can lead to installation problems.

This is the case when the interface is in the area of the close-fitting trim panels.

Find matching interface (e.g. approx. 10 cm behind rear seat backrest in E46 touring).

Lay repair cable parallel to battery positive lead.

Mark interface of battery positive lead at end of repair cable.

Release cable ties (1).

Disconnect plug connection (2).

CAUTION: Do not use bolt cutters or similar tools to cut through the cable.

A cable end that has been squashed flat will no longer fit into the clamping sleeve.

Saw through battery positive cable at marked point with an iron saw.

Strip insulation - length (A) - from cable end.

Distance (A) = 15 mm.

Push heavy-current connector (1) over stripped cable end and screw into position.

Push shrink-fit hose (3) over repair cable.

Screw threaded sleeve (1) of repair cable (2) to heavy-current connector.

Push shrink-fit hose (1) over connecting point and shrink on with a hot-air blower (2).

NOTE: Heat up shrink-fit hose until it has settled completely around the connection point.

When laying the repaired battery positive cable, observe the following:

• The shrink-fit hose must not be scuffed during any movement.
• The repair cable must not cause any disturbing noises during driving operation.

NOTE: Offsetting cutting line by approx. 10 cm produces excess length of battery positive lead (1).

Lay battery positive lead (1) without kinks or abrasions.

(Shown on E46 touring.)