335i N54 - Overcharing Alternator - Replace whole thing?

[moebiusuk]

A couple of days ago, my 335i started acting very strangely. Dash lights going crazy, windows and lights not working, even the fan wasn't working as it should so the car was overheating. I shut things off immediately and called AA who ran some tests and found that the alternator was overcharing at 16.5v. He disconnected the alternator and I managed to get home on battery alone.

Anway, I've been looking at alternators and genuine BMW one is rare but the ones found were £800-£1200. But there are alternatives at £250-£350. Questions are:

Do I need to replace the whole alternator or just the voltage regulator?
If I do need to replace the whole alternator, getting a non-BMW (Bosch) one should be OK, right?

[Aluminati]

The voltage regulator controls the output of the Alternator. If you have the ability to change this, you’ll be quids in.

OEM are usually Valeo or Bosch from memory.

[Sir_Dave]

This happened to my 335i a couple of weeks back ... well the opposite in fact, i wasnt getting any battery recharge, but anyways ...

Most people told me to change the whole thing, which not only costs a fortune, but is a pain in the ar5e.

I swopped the regulator over in about 10 minutes and problem solved for 40 quid.

Checkyour part numbers, but this was mine: https://www.onlinecarparts.co.uk/bosch-777195.html

[moebiusuk]

Thanks everyone!

My mechanic told me to replace the whole thing too but I'm just going to replace the regulator.