2004 M3, battery light coming on at "high" revs?

"Fred W" > wrote in message
. ..
> wrote:
>
>>
>> The drive belt is what is commonly termed "fan-belt" and is a black
>> rubber thing
>> that runs around various pulleys on the front of your engine.
>>
>> To test the tension you need a measuring stick and a strong thumb -
>> ENGINE MUST
>> BE STOPPED.

Or you are not going to have a thumb (or in my mates case the end of his
little finger).

"daz" > wrote in message
oups.com...
> On 6 Jun, 00:24, "Dave Plowman (News)" > wrote:
>> In article >,
>> > wrote:
>>
>> > If you don't know how to adjust then find someone that can. I also
>> > suggest that you get a new belt fitted anyway.
>>
>> Hasn't it got a serpentine belt like most modern BMWs - self tensioning
>> via an idler pulley - and with a life of approx 70,000 miles?
>>
>> --
>> *If a turtle doesn't have a shell, is he homeless or naked?
>>
>> Dave Plowman London SW
>> To e-mail, change noise into sound.
>
> Just an update for those interested.
>
> Turned off the motorway today and battery light came on constant, took
> it to a friends garage and the battery showed at 11 volts, he said it
> should be 12.something without the engine running and 13 (or was it
> 14). something with engine running, so the alternator has gone, damn
> it!!!

Might be the battery, although the symptoms suggest the alternator.

>
> Thanks for all the replies, much appreciated.
>
> Daz
>