E46 320d dies while running and dead battery

Twinz

Forum - Support
Staff member
Get the car to a good workshop and have it properly checked. Its always hard to diagnose and sort out a car remotely.
 

kingr

BMWFanatics Advertiser
Official Advertiser
As mentioned, a faulty ignition might the problem. If it fails in the “on” position its equivalent to switching your car off while driving.

I would first diagnose the alternator though. You can test alternator with a multimeter. A bad ground connection from your battery to the body can also cause this issue because, so inspect it and all wiring running to/from the alternator.

Here’s a diy vid to test the alternator
 

Theksteen

New member
Hi Rooibaard, did you manage to resolve your battery going flat while driving problem? I'm enquiring as I have the same problem with my e90 320d and not sure what is the cause. Was hoping I could get some useful info from you maybe. Kind regards Theuns
 

ROOIBAARD

New member
I cleaned the contact points on the negative cable between the battery and the body,that seemed to solve the problem. Please let me know if this solved the problem for you
 

Theksteen

New member
Ok, thanks, I will try that and see. Will let you know. Mine seem to be more related to heat, so when my car is hot, after driving and then also external temperatures, the alternator does not switch on. I have replaced the battery and the regulator on the alternator. But problem still coming back intermittent. Thanks for coming back to me, appreciated.
 
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