It's not really a matter of if, but rather a question of when the alternator Rotor on your boxer will fail. Once you have determined that you have a problem with your charging system, it's rather easy to determine if the rotor is the problem or a part of it, as long as you have access to an Ohm meter. Remove or insulate the brushes and test for continuity between the slip rings. If you instead have an open circuit then the rotor needs to be replaced or repaired.
There are several options available. BMW sells this part for over $450.00. There are expensive electronic conversions that claim to put an end to the problem once and for all. You can also purchase rebuilt rotors or have yours rewound. The option that we offer is simple: This is a brand new, not re-built, European made rotor that will fit all model year 12 Volt boxers from /5 an onward. This is a high quality reproduction part that will offer many years of reliable service.
Equivalent to BMW part # 12 31 1 244 642 (12311244642)
NOTE: Removal tool available under Related Products above.