12 31 020 Removing and installing or replacing alternator (S65)

WARNING: This page is about a different car, the 2011 BMW M3, 2010 BMW M3, 2009 BMW M3, and 2008 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.

Necessary preliminary tasks:

Switch off ignition
Disconnect BATTERY NEGATIVE LEAD .
Remove air filter housing . See 13 71 000 REMOVING AND INSTALLING/REPLACING INTAKE FILTER HOUSING (S65) .
Remove underbody protection . See 5147 FLOOR, LUGGAGE COMPARTMENT, ENGINE COMPARTMENT, TRIM PANELS .
Remove alternator drive belt . See 11 28 010 REPLACING ALTERNATOR DRIVE BELT (S65) .

Release screws.

Unclip hoses from hose holders on radiator.

Carefully press leads (1) to one side.

Fig 1: Locating Screws

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Release screws.

Pull alternator (1) forwards until connections are accessible.

Fig 2: Identifying Alternator

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Unlock plug (1) and remove.

Release nut (2), remove battery positive lead from alternator.

Tightening torque 12 31 1AZ , see 12 31 ALTERNATOR WITH DRIVE AND MOUNTING PARTS .

Pull alternator (3) upwards to remove.

Add final details to vehicle.

Read fault memory.

Fig 3: Identifying Alternator, Plug And Nut

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