1988 BMW 528 Battery going dead while dfriving

1988 BMW 528
12,000 MILES • 6 CYL • 2WD • AUTOMATIC
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DJALBERTDESIGN
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I now own a second hand 1988 BMW 528e. The car is in great condition and i love it except that it doesn't run for long.
When I drive the car runs without issues until the speedometer starts to go crazy as well as a few other gages. Within minutes of that happening the cart stalls and cannot be started without a jump start or charging the battery. Allowing the car to idle or to drive with everything off allows the battery to recharge.
I have not been able to isolate where the drain is.

Can you provide me any guideance on where BMW's may have had a shorting problem, or any information on what you think the issue is.

I have checked for current draw at the fuse box in the engine compartment and cannot find a circuit that is draining while the car is off.

The issue must be a high drain to make the battery go dead whilr the charging system id running. I have a new battery and alternator and still the same problem.

Thanks for any help you can provide.

Dave Jalbert
401 615 3353
Oct 22, 2008 at 3:27 PM
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MASTERTECHTIM
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im assuming the problem is the charging system. possible defective? recheck connections. the gauges are going crazy from the alternator not charging.
Oct 22, 2008 at 5:26 PM
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DOCHAGERTY
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It is possibly the brush pack and not the alternator. The part # is 12-31-1-726-022. This part can be installed without removing the alternator.
Oct 22, 2008 at 6:38 PM
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DJALBERTDESIGN
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I have already replaced the alternator and battery. its possible the new alternator is defective as well.

What is a brush pack?

any other ideas?

Thanks

Dave
Oct 26, 2008 at 10:41 AM
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DOCHAGERTY
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It is possible the new alternator is bad. Take it to the seller and get it checked
Oct 26, 2008 at 3:18 PM
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DJALBERTDESIGN
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I will do that. I did the battery voltage test yesturday and the voltage was not steady at 13+ volts, it just kept dropping with time
Oct 27, 2008 at 7:50 AM
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DOCHAGERTY
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You may also have a parasitic draw that is killing the battery.
Nov 6, 2008 at 10:44 AM
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DJALBERTDESIGN
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It turned out to be the new alternator was bad. it has been replaced and the problem seams to be gone.

Thanks for your help
Dave
Nov 6, 2008 at 10:55 AM