This voltage regulator was used on the electrical charging system and installs on the backside of the alternator.
Only for cars with Valeo brand alternator.
Charging issues are not always a "bad alternator". The voltage regulator is located on the back of the Valeo alternator and it regulates the output voltage produced by the alternator. A bad voltage regulator can fail to charge the battery at a sufficient rate (slow drain) and it can also allow too much voltage to enter back into the rest of the electrical system where it may damage voltage-sensitive components. Rebuilt alternators will include a new, or tested and approved, voltage regulator. But if you believe the alternator is good, the regulator can be replaced on its own to avoid a bigger repair bill.
Note: electrical parts cannot be returned once purchased. While this is often a good "first try" part for fixing bad alternator voltage issues, if this doesn't solve your issues you can't simply send it back. We can't take used/tested electrical components back as it's not fair to the next customer to get anything other than a new / tested unit. On the bright side, if you end up replacing the complete alternator, you'll already have a voltage regulator.
Voltage regulators often vary by alternator brand and output. This part number replaces, or is compatible with, BMW/Valeo part numbers 12 32 1 739 435, 12311437340, 12311735788, 12312244626, 12317789332.
BMW Fitments:
3 Series
E36 (92-99) > 318i M42
E36 (92-99) > 318i M44
E36 (92-99) > 318ic M42
E36 (92-99) > 318ic M44
E36 (92-99) > 318is M42
E36 (92-99) > 318is M44
E36 (92-99) > 323ic
E36 (92-99) > 323is
E36 (92-99) > 325i
E36 (92-99) > 325ic
E36 (92-99) > 325is
E36 (92-99) > 328i
E36 (92-99) > 328ic
E36 (92-99) > 328is
E36 (92-99) > M3 (1995)
E36 (92-99) > M3 (96-99)
3 Series
E36/5 (95-99) > 318ti M42
E36/5 (95-99) > 318ti M44
5 Series
E34 (89-95) > 530i
Z Series
E36/7 / E36/8 Z3 (96-02) > Z3 M - S52