2000 5401a Complete Electrical Shut Down

[Hobokenguy]

I'm looking for any other BMW folks who have experienced the above. I have a 2000 540ia with 29,000 mi. Always dealer maintained. It has a nasty habit of complete electrical shut down while driving. When this happens, with no warning, all juice in the car is gone. No dash lights, no flashers, no ingition response, windows etc. Completely dead. I just put in a new battery two days ago and it happend again today, in traffic. It has happened a number of times before but would restart after a few minutes. This time not at all. After towing it to a near by sears to do a quick diagnostic on the alternator it was determined that the alt and battery were fine but did diagose an "excessive voltage drop" and died twice while the tech was working on it. While it was in the bay I tried starting it and it did turnover but shut down within seconds. It is now at JMK BMW in Springfield NJ and I was hoping to get feedback from anyone who is knowledgeable about what appears to be a systemic electrical malfunction. Thanks and good driving..............

[alex boss]

My sons 540 had a prob where the car would shut down while driving and the seats and steering wheel would act as if he turned off ignition switch. Turned out to be an ignition module down on the steering column. Cost $70 plus and instant fix. HTH