12 31 020 Removing and installing or replacing alternator (N54)

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Necessary preliminary tasks

Turn off ignition
Disconnect BATTERY NEGATIVE LEAD and cover
Remove INTAKE FILTER HOUSING
Release CHARGE-AIR DUCT at front, do not remove
Remove alternator DRIVE BELT

NOTE: In order to remove the alternator, it is necessary to remove the air-conditioning compressor for the air conditioning system.
In so doing:

Do not draw off A/C system refrigerant.
Do not detach refrigerant lines from A/C compressor.
Do not remove A/C compressor; instead, remove from bracket only and place to one side.
See 64 52 521 REPLACING AIR CONDITIONING COMPRESSOR (N54) .

NOTE: For purposes of improved clarity, illustrations and description show A/C compressor removed.

Release bolts a few turns until bracket (1) is loose. Do not remove bracket (1).

Tightening torque, see 64 52 A/C COMPRESSOR .

Fig 1: Locating Bracket Mounting Nuts

Courtesy of BMW OF NORTH AMERICA, INC.

Unlock plug (1) and remove.

Remove protective cap (2) and release nut underneath.

Tightening torque 12 42 1AZ .

Remove battery positive lead.

Release screws (3).

Tightening torque 12 31 1AZ .

Tightening torque 12 31 2AZ .

Remove alternator.

Fig 2: Identifying Alternator Plug And Protective Cap

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.