How to Replace a BMW X5 Alternator


Removing the Faulty Alternator
1. Park your BMW in an area where the front of the vehicle is openly accessible.
2. Turn off the engine. Pop the hood and remove the negative (black) terminal from the vehicle's battery using a crescent wrench.
3. Climb under the vehicle and locate the swing pulley along the serpentine belt assembly. The swing pulley is slightly larger than other pulleys in the assembly and is located on the end of a long arm. It is also accompanied by a brass bolt end known as the 'auto tensioner.'
4. Connect a crescent wrench to the auto tensioner and twist it counterclockwise. While keeping pressure on the tensioner, slide the serpentine belt off the swing pulley.
5. Climb out from under the vehicle and locate the alternator. This part is vented and made of aluminum. It is located at the top of the engine carriage assembly and is connected directly into the serpentine belt assembly.
6. Remove the electrical connection on top of the alternator using a 12 mm socket wrench.
7. Remove the four mounting bolts around the edge of the alternator, once again using a 12 mm socket. Then slide the alternator out of the engine housing.
Installing the New Alternator
8. Slide the replacement alternator into its housing. Then replace the four mounting bolts you just removed.
9. Slide the serpentine belt over the alternator's drive shaft.
10. Climb under the vehicle and connect a crescent wrench to the auto tensioner once again. While keeping counterclockwise pressure, slide the serpentine belt back over the swing pulley.
11. Reconnect the electrical end on top of the alternator.
12. Replace the negative terminal on the vehicle's battery.