[bmwheath]

So, went to start my car the other day and battery was flat, very strange as the battery is less than 12 months old & genuine bmw.
So i charged her up over night, started it a couple days later & threw a multimeter on the battery to see if the alternator might not be charging. It was actually over charging (18.5 volts from memory!).
I took it for a quick drive yesterday and strait away started to realize shit wasn't right. I had no idrive screen, then gearbox light came on and stuck in 3rd gear, no indicators, wipers, sunroof, windows, speedo, static through the speakers etc etc, the list goes on.
I didn't realize in the video that i was getting the water temp light because the electric water pump wasn't working either! Lucky i pulled over strait away and was only 4-5 mins from home so all good.
I wont be driving it again till i get it looked at otherwise ill end up cooking my new battery as well.
Before this the car was running great, no issues apart from the Steering angle sensor giving me ABS lights on the dash.
Just another fun day owning a modified 335i. Im sure its something simple like a wire earthing out and causing electrical mayhem.
Ill keep you guys posted on what it ends up being
Watch both videos below:

[BMJ]

i was in a similar boat. didn't drive the car for a while went to crank it and shit just went haywire car made some funny clicking noises.

had one low battery charge warning a little while before that never came back. i did notice my Comfort access stopped really working. (thought it was the key battery.)

OE batteries are shit. i bought a gen bmw battery off southern BM, they told me supercharge sucked and i had to go OE the POS they sold me didn't even last 4 years... waste of $500. avoid SBM is my advice.

Bought a supercharge for $299 and fitted it myself (was a interesting job) took me a couple hours as I was doing it slow and steady. on the back of the positive pack there's a small wire don't break it!

once new battery in CA back to lightning quick and car started in a second. Also wasn't able to keep power car went completely off. not to worry all my radio stations stayed saved only thing that reset was the time and date. so again SBM old me it haaaad to be done cant just swap out.

long story short... change your battery man!

[PG]

So after my walnut blasting I had a very similar thing happen. Car would not respond to the throttle and CELs everywhere. All it needed was the battery to recharge overnight. Maybe it's just a new battery then?

[EB89]

If it happened after changing the battery could you have messed something up in the trunk?

[vtl]

Did you charge the battery from the terminals under the bonnet or directly accross the battery terminals? You are only supposed to charge the battery from the charge terminal under the bonnet. Only charge the across the battery terminals directly if its disconnected from the vehicle.

[bmwheath]

Thanks for the input guys. There's no issue with the battery. Its only 12 months old and holds charge perfectly fine, it cranks over fast and starts 1st go.
It all started from this 1 time i went to start it and it was flat for an unknown reason.
We had to jumpstart the car directly from the battery in the boot as our jumper leads were to short to reach under the bonnet because of when the car was parked.
I drove the car home & the battery was flat the next day.
I then charged it overnight direct to the battery but with the negative terminal disconnected.
If i disconnect the negative battery terminal the battery will NOT go flat if it let the car sit for days. If the battery is connected it goes flat overnight. No accessories are left on that i know of.

Thanks for the heads up VLT as i completely forgot your not meant to jumpstart direct from the battery! (blonde moment)
I have so many old and new cars and im just used to hooking up to the battery when are car is flat, i should know better grr..

[bmwheath]

Hopefully its just a voltage leak at a minor component, more than likely fried a relay or switch that is now draining the amps from the battery

[vtl]

Best way to diagnose would be to set your multimeter on amps and hook it in between the positive terminal of the battery to the battery positive cable. Then watch the reading of the current draw as you start to pull fuses. You can start to isolate the issue that way.

[Socket]

jebus Heathy,,, ur car is possessed bro .... clearly an electrical problem ...

[Socket]

Seriously now

Could be the voltage regulator..... here is link to a thread with someone that looks to be having a similar problem. Post 22 seems to have the answer

http://www.e90post.com/forums/showth...hlight=voltage

[bmwheath]

Originally Posted by vtl

Best way to diagnose would be to set your multimeter on amps and hook it in between the positive terminal of the battery to the battery positive cable. Then watch the reading of the current draw as you start to pull fuses. You can start to isolate the issue that way.

Thanks VLT, yeah i was going to try isolate where the issue was coming from but ill just let my mechanic sought it out as im far to busy to deal with this stupid Bmw electrical demon lol. Hopefully its just the voltage regulator on the alternator but i have a feeling its going to be something stupid like a fried switch circuit for like the powered seats or something, as its leaking voltage while batteries connected.

[bmwheath]

Originally Posted by Socket

Seriously now

Could be the voltage regulator..... here is link to a thread with someone that looks to be having a similar problem. Post 22 seems to have the answer

http://www.e90post.com/forums/showth...hlight=voltage

Thanks Socket, i had thought about it just being the voltage regulator but i have a feeling it maybe something else elec related. im going to tow it to my mechanic on Monday. Hopefully he can isolate the issue & it doesn't cost more than 4 million dollars to fix

[Flex68]

Very very strange issue please keep us updated as very keen to know the source of the problem

[_ink]

I hope it all works out OK and isn't an expensive repair, i think your jump start directly at the battery would have caused something to fry.. Either what Socks has pointed out, or the FRM module maybe..

G'luck mate.

[Boganian Rubes]

Seeing this thread before buying 335i be like

Haha jk goodluck with fix heath

[Midlife_C]

Originally Posted by Rub3n

Seeing this thread before buying 335i be like
Haha jk goodluck with fix heath

Lol I have been reading threads like this and still bought it!

Good luck with fixing the car Heath, let's hope it's something simple.

[bmwheath]

Just an update for anyone following: the mechanic has traced the fault back to the alternator (which i had a feeling it was going to be) Got quoted $1000 for a Bosch, i ended up ordering a 2nd hand one from ASV Euro Parts for $275 delivered. Will fit it up in the next few days, clear some codes etc and see how we go. I have a feeling there may be other things to diagnose, but well see how we go : )

[Viorage]

So my battery seems to be having the same problem. I jumped it and ran it for about an hour, got home turned it off and tried to start it but it was dead again. I thought the battery was just dead.

So you are saying it might be electrical? Does this sound like your problem?

[bmwheath]

Originally Posted by Viorage

So my battery seems to be having the same problem. I jumped it and ran it for about an hour, got home turned it off and tried to start it but it was dead again. I thought the battery was just dead.

So you are saying it might be electrical? Does this sound like your problem?

You would need to check if the alternator is providing charge to the battery, throw a multi meter across it, there is also a hidden menu that can display the voltage on your dash (just google it), though i have never used it.
You issue may be alternator, battery, or 1 of the other 30 thousand issues these cars have lol

[Viorage]

Originally Posted by bmwheath

You would need to check if the alternator is providing charge to the battery, throw a multi meter across it, there is also a hidden onboard volt ready that can be displayed on your dash, though i have never used it.
You issue may be alternator, battery, or 1 of the other 30 thousand issues these cars have lol

Crap I guess I'll have to take it in. Thanks

[Scotty89]

Originally Posted by Viorage

Crap I guess I'll have to take it in. Thanks

Don't take it to the dealership.

[Viorage]

Originally Posted by Scotty89

Don't take it to the dealership.

There are some local guys that might be willing to help