Help?! E46 All warning lights on/Speedo stopped

[LJJane 0]

Hi everyone,

reasonably new here, sorry if I put this in the wrong place, but figured that it would be an electrical issue.

It's been parked up driveway for 4-6 months while I saved funds for new diff (this is a long story, not getting into it). I've been regularly turning engine on every week or two while it was parked up and everything's been fine.

However when I was driving it today after I picked it up from workshop the battery light came on.. and then the airbag light, and the stereo turned off and then the headlights went dull. The ABS said it wasn't working then DSC light came on along with all the other usual suspects...

Also then I noticed that even though I was parked at side of road speedo said I was going 80km/h and doing 2,500revs which I clearly wasn't.

Turned car off and now it wont start... Any ideas?

[euroriffic 603]

I just had the same issue with the m3. Was the alternator not charging properly so the battery kept dying. Check the belt that runs the alternator is tight first as that can cause the issue

[LJJane 0]

Yeah I did I basic check before and went over everything, all fuses seem to be fine and everything is connected properly. Looks like the belt is fine as well but it's quite late so I might need to wait for the morning. Hopefully I can start it in the morning depending how temperamental it wants to be.

[hybrid 1039]

Probably your batteries load capabilities are on the way out. However after you get the diff sorted. Get it scanned by proper BMW specific diagnostic software. It will most likely bring up the symptoms in real time or at least as a stored fault.

[blonky 2]

Could also be a bad ground connection; usually between the battery and chassis

[Lukeprusher 13]

Quick question do you have a multimeter? If so measure battery and then turn car on and headlights and see what reading you get as this should draw current and kick start alternator should then measure between 13 to 14.5v if less alternator has problem if between figures check the starter motor.

Edited June 12, 2013 by Luke Prusher

[LJJane 0]

Hey All, ends up the battery and the alternator died , getting them replaced today . Ended up taking it to closest mechanic to my flat which happens to be Alfa specialist, so I figure they'd know if it was an electrical issue lol.

It got hit by a truck back in November last year and I've been fighting with insurance company since then to repair mechanical faults, hence it got stuck up my drive for 8 months. I figure moisture must have made its way into the alternator or something similar and battery died on own accord.