Alternator Failure???

Hi Everyone

So yet again the old fella (2001 2.5 Diesel) has let me down on the M3 25 miles from home.........

Driving along quite happily at about 70mph, then there was a blip from the warning buzzer and the tachometer started waving around wildly ABS and TC warning lights came on, then I lost the tacho, speedo, and HVAC display and gradually the lights started to fade, I guess I was driving on the battery and eventually he ground to a halt.

No ALT light came on but I am assuming the alternator has packed up?

Any advice before I spend 2-300 on a new unit, the vehicle is now completely dead (electrically)

Battery is relatively new and of good quality, all leads and earth connections are good

Many thanks

Sounds Alternator related...

You may be lucky and get away with just replacing the diode regulator pack on the back....others will be more knowledgable on that then me....

BUT Island list at £166 for a new Alternator (no affiliation)

Alternator 2.5 TD BMW STC2227 Island 4x4 - Specialists in Land Rover and Range Rover Parts and accessories for all models. UK and worldwide mail order.

Hi Saint

Yes thanks for that link, I have bought all the gear for this car from island they have been very good........

I was this close to buying the alternator as preventative maintenance.........and didn't!!!

AP90 said:

Hi Saint

Yes thanks for that link, I have bought all the gear for this car from island they have been very good........

I was this close to buying the alternator as preventative maintenance.........and didn't!!!

Click to expand...

That is 'Sods Law' in operation....

What for the likes of Wammers or Datatek to confirm Diode/Regulator pack replacement (if at all possible) first before you shell out on a replacement unit...it could save you a bob or two..

I had exactly the same symptoms on my 98 DSE. Everything started to shut down gradually (tach/speedometer, hevac, radio, all internal lights) but I managed to drive home with just the front fog lights on (the dipped beams had gone by then). No alternator light or warning ever came up.

Dropped it at the local sparky who refurbed the alternator and all was good

yes exactly that..... like in a dingy shipping water trying to make the shoreline knowing it just isn't going to happen.

Strange there was no alt light, I know it works.....

If only I had changed out the alternator!!

Diode pack, regulator and brushes if you want to do an overhaul and check the slip rings are not too worn. worth fitting new bearings if you decide to do it. Much cheaper than a replacement. However it is not unknown for the windings to fail, in which case they usuall look a bit black and may smell of burning. Check before you buy the bits.

Thanks Data

But I have just bought the one in the link Saint detailed........

Along with blend motors and some aircon bits. I intend to sell the car on now so it will be in good order for the next owner, great looking car, rides great with new suspension and all the work I did on the front of the engine, but I am not happy to take it on the frequent visits to Cornwall from London for fear of breakdown. I have had 3 breakdowns in 33 years of driving........ 2 in this car in the space of 6 months. not great.

Hi

The alternator arrived this morning and took about 40 mins to replace it and re fit the now recharged battery.

All seems fine now, odd that there was no ALT fault light when the old one packed up.

The throttle response is now slightly better, makes me think that the voltage was a little down across the whole system?

Thanks for all the advice everyone

Will I keep this car...........???????

Ash

Just sent you a pm to see how things are going and then spotted this thread! Oops! Keep your chin up!

AP90 said:

Hi

The alternator arrived this morning and took about 40 mins to replace it and re fit the now recharged battery.

All seems fine now, odd that there was no ALT fault light when the old one packed up.

The throttle response is now slightly better, makes me think that the voltage was a little down across the whole system?

Thanks for all the advice everyone

Will I keep this car...........???????

Ash

Click to expand...

The becm needs to see a gnd signal on the charge warning lamp input from the alternator before it will put up a warning message on the ipack. When everything is fine and the alternator is charging then there will be Vbatt on this input wire. With some alternator regulator faults, this signal can be open circuit which means that the becm does not receive the gnd signal to switch on the warning message (which is what has happened in your case).