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FREE SHIPPING on US orders over $75 (oversize excepted) • Quality used E36 & E46 parts • Every part inspected & graded
3 Series Parts

Voltage regulator

BMW Part Number:12 31 7 540 657
12317540657short number 7540657
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Genuine BMW Part

Photos coming soon — see the BMW diagram below

Voltage regulator – BMW diagram05 View BMW DiagramSee this part on the official exploded view

This is a genuine BMW voltage regulator, part number 12 31 7 540 657. The number stamped on the part is 12317540657; BMW's catalog files it under the short number 7540657. You will find it on our Electrical shelf, under Alternator with motor and mounting. It supersedes the older number 7542530, so a part carrying that number is the same part.

BMW's catalog records no E36 or E46 it is fitted to; it belongs to other BMW models.

BMW draws it on 2 diagrams, among them Generator, individual parts (12_1245) and Alternator 140/150A (12_1310). It weighs about 80 g (0.2 lb).

We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.

Details

BMW Part Number12 31 7 540 657
Also written as123175406577540657
QualityGenuine BMW · OEM

No fitment data available for this part.

Every used part is inspected and graded before listing. Condition grades:

  • Good — minimal wear, fully functional.
  • Fair — normal wear, fully functional.
  • Acceptable — visible wear, still functional.

Returns: 30 days if a part arrives damaged or isn't what the listing described. Full policy.

Shipping: Ships within the US. Orders ship within 1–2 business days; small parcels ship free on orders of $75.00 or more. Oversize items ship at a flat $49.99 each — free shipping does not cover them.