Replace voltage regulator, or whole alternator?

[RossBMWZseries]

Thanks for the response guys. I brought the Z4 to work today and I'm out to lunch, so I'm going to head out right now and see if it starts. The last thing I want is a coworker having to jumpstart a BMW, I'm going to hear it tomorrow lol. For the record, sometimes it dies as quick as in 2-3 hours of not driving it, not just a 12 hour window

[Shipkiller]

If the battery is becoming discharged after two or three hours (sometimes), then you should be able to find the issue rather quickly. The problem child should be really HOT with that sustained high discharge rate......

[RossBMWZseries]

You're probably right Shipkiller. I just think that at this point my frustration is not allowing me to think and quickly get fed up with the car

[RossBMWZseries]

Soooo another day gone by with no solution. Haven't jump started the car today as there was no need but my AC still isn't working in this 95 degree day. Fuses seem to light up steady, battery voltage is on point (testing from the dash itself). Maybe somehow the jumpstart put it on transport mode..? Which I'm still unclear as to how that works. I read somewhere in forums that disconnecting the battery and touching both negative/positive cables will do a "master reset" and could do the job. Not sure how I feel about dying though. The only thing I accomplished was to break the left side hinge from my passenger compartment, now It's sagging like the common issue on Z3's. I'm gonna call it a night, take a cold shower, curl up in a fetus position in bed, and cry the night away. Cheers guys!

[jdoege]

This is a bit late, but have you considered measuring the current through each individual fuse with an ammeter? There should be almost no draw when the ignition is off so anything over something less than an amp would be a clue as to what is drawing power.

[RossBMWZseries]

Originally Posted by jdoege

This is a bit late, but have you considered measuring the current through each individual fuse with an ammeter? There should be almost no draw when the ignition is off so anything over something less than an amp would be a clue as to what is drawing power.

Hey bud, very late indeed lol. Thank you anyway for your input, I got this resolved. It was my OEM Navigation that was staying on even when the car was off and was killing the battery. Navigation is now disabled.

[Finnegan]

Originally Posted by RossBMWZseries

Hey bud, very late indeed lol. Thank you anyway for your input, I got this resolved. It was my OEM Navigation that was staying on even when the car was off and was killing the battery. Navigation is now disabled.

Given how archaic the nav is that seems like a good move.

[duke48]

My charging light has been on in the morning. Goes out after a mile or so. battery registers 12.4 V Battery charging 14.3 V. What the....?????

put a 2 hr. charge on the battery and the light was on when I went to start it. Went out per usual.

[AK72]

Originally Posted by CJW2OO4

Did you guys experience the brake lights and the music and corner lights cut in and out?

My car have exact symptoms + throttle adaptation value errors with reference to terminal 15 = alternator

[kyriian]

Originally Posted by duke48

My charging light has been on in the morning. Goes out after a mile or so. battery registers 12.4 V Battery charging 14.3 V. What the....?????

put a 2 hr. charge on the battery and the light was on when I went to start it. Went out per usual.

I did
I had my alternator rebuilt and is now mint again

[eruiz]

Does anyone have the P/N for the voltage regulator? My Z4M is starting to show the same trouble, I want to try with the regulator first, but can´t find it on REALOEM.

Thanks

[AK72]

Unfortunately BMW stop selling voltage regulator separately # 5 on the picture,
but you can try this guys - https://www.maniacelectricmotors.com...-bearings.html