E34 540 Electrical Woe.

[540red]

I am in love with my 540 but it occassionally doesn't return the feeling. During the day, everything works perfectly and there are no errors or even trembles but come night time, it does a Walter Mitty on me. If you have the headlights on, no worries but if you do anything else like brake, indicate a turn or use the wipers as well, the dash starts bonging and bulb failure messages start coming up. As the sensors measure voltage flow, I thought maybe the bulbs were on their last legs so replaced them all but, no change. I hasten to add, the bulbs ARE still working fine while all this is happening. Is this common and apart from a big hammer, are there any suggestions. Thanks.

[marti5]

Alternator not pumping out enough.

[540red]

Ah ha, that will account for my battery dying a couple of weeks ago. Thanks for that.

[marti5]

Or it could be your battery thats got a bad/dead cell, if the batts older than 3yrs or you do alot of short journeys this could be the case, best thing to do is take it to your local battery place and get them to test the Alternator and Batt, its deffo one of the two,how the alt works is it runs the car electrical system and anything left over it pumps in to the batt.

Thinking about it with your mileage so low I would go for the battery.

[540red]

Again, thanks. I had replaced the battery at a NZ$400 cost because it was dry and dead. I don't think the previous owners knew where it was, and, it is still doing it so it must be the other.