[zygimantas]

Today I tried to check my voltage regulator brushes on my n54, because when my car is running I only get 13.82- 14 volts on battery ( and battery is only charged to ~10%, so I should get more). So I removed air box, black cover from the back of alternator and I tried to loosen the 4 bolts which hold voltage regulator, but none of them moves, looks like they are stripped. So before I ruin them I tried to look where do I get new ones, but with no luck. Does anyone know where to get new bolts? Two are longer and two are shorter.
Or maybe bolts are not completely stripped, because when I put my torx in the bolt and try to turn ir goes back a little and then turns without a bolt. So maybe I just need better tools?

[marvinstockman]

Zygi, your alternator voltage is fine, but I would check the battery, cables, and connectors.

Get something like this, and check you're voltage while driving:

https://www.amazon.com/LIHAN-Charger...6&sr=8-15&th=1

[mainbearing]

+1 those voltages look ok. Make sure the battery is getting that power.

When I changed my Bosch 180 regulator was because I was getting hidden codes on alternator over voltages (16-17v). There were a couple of misfires, but strange I did not get a MIL light on those. Check Control messages always said OK. I only stumbled upon these codes with a scan.

I do not think you can buy those bolts even from the dealer, because they only sell the whole alternator. Take them to a parts store to match up. Metric bolts are hard to find if they are not the more typical sizes and lengths, but you can search eBay too.

[ctuna]

RealOem.com can tell you the size at least.
Use the right socket and get some CRC knocker loose.

Or this is a new one

or
https://www.amazon.com/Knocker-Penet.../dp/B07J485Q31

But your voltage is good.
Did you measure the voltage at the battery .
Is there a drop from the alternator you could have a bad ground strap to the engine.
You can't leave these cars set and you must do some significant highway miles to keep the
battery charged . If you can't then you must use a battery tender part of the time.

[zygimantas]

Yeah, probably a good idea. Gonna check if wires and connection around battery are not coroded and measure voltage at the battery ( I used Inpa to measure first time). Anyways, I think that at low charge, when car is running I should be getting 14,4 v. So that's why I suspected voltage regulator.

[CoralRed335XI]

The lower passenger side bolt seems to always be very snug. It threads into a coil of solid copper cable, not an actual nut or threaded hole. I’ve used some penetrating fluid and a couple taps with a hammer and punch to loosen it up.

I couldn’t find just the replacement bolts from an OEM supplier, but to have a kit of stainless metric bolts. I believe they are M3 threads.

[Bmw2007]

Are these bolts only to hold the regulator down or do the close a circuit?

My screw broke. The regulator looks reasonably secure but I'm not sure if the screw is essential for the regulator to work .