E60Japanese

Hi everyone
I thought I would write a small update on my E60
It is all good so don’t worry lololololol

I had a problem with my electrical system (the final problem to fix before registering it and the government inspection)

The battery would take a charge from a battery charger but I would drive the car just a little and it would be flat again
I tested it with a Multimeter and the battery was okay but not great

I bought a new battery and a new alternator
The alternator was charging okay but both bearings were noisy and so it was not much more expensive to but a new one.

But even thought all the electrics were new I was still having trouble.
The charge was not consistent
The mulimeter would show the charge going up and down with sudden huge drops in power.

The problem in the end was the single excite wire that plugs into the back of the alternator
The plastic around the wire was hard and the wire had broken inside causing the alternator to charge when the wires touch spasmodically

I replace about 300mm of the wire and the problem was fixed
Now I have a perfect electrical system again

I also took the car to a Government inspection and it passed no problems

The transmission continues to work perfectly also
I am very happy to drive such a beautiful car now

A big difference from when I bought the car broken three months ago
And a huge difference from the $20,000 repair bill from BMW and the $2,000 parts cost of doing it myself

Thank you everyone for your help and advice
I hope I can also pass on my limited but growing knowledge on these great cars to others
Thanks

wcr3d

Good work tracking that down. Nice break being a cheap fix too. Post up some pics.

pcy

Is the problem with the new alternator or with the voltage regulator or with the wire connection?

E60Japanese

Hi
The alternator was working okay but the front and rear bearings were noisy
I checked the regulator and the bushes were both okay as well
In the end it was only a little more money to buy a brand new alternator than just replacing the bearings and having the car off the road for a week while it was being repaired

But I wasnt aware of the broken wire untill I had fitted both the new battery and alternator

The problem in the end with the charging was the broken excite wire
The excite wire is a simple power wire that is usually run from the ignition switch
(not sure if it is also run from the same position on the E60)
so the excite wire just tells the regulator to start working when the car is running

I removed the wire from the alternator and tested it but it didnt have power
but i moved it a little and it had power

I replace the hard plastic cracked section of the wire and everything was perfect again.

I had a similar problem when I had the front pulley belt and water pump removed

Two wires run from the alternator side of the engine to the other side of the engine run in a black plastic protective cover

The cover was hard and broken exposing the wires for about 400mm

I tested both wires and they had not yet become hard or broken
I recovered them in new plastic tubing before I replaced the water pump and belt

I dont know if this is a problem with E60's but it is something that I am now aware of with my car

E60Japanese

Im really happy with the car. thanks for your encouragment