Battery warning light on '93 E36 occasionally lighting up

I have a '93 E36 320i SE, and yesterday I noticed the battery warning light
come on while driving. A few seconds later it went off again. Parked up, did
some shopping, came back, started the car up as normal and the light stayed
on rather than going out as it does normally, although it was very faint and
kept flickering. A few minutes later it went off again. It seems to come and
go, driving to work this morning it popped up again. I haven't got a
voltmeter so I can't dig around testing various parts of the charging
circuit, any ideas what I should be looking for? Is it possible some damp is
causing a short? (it's gotten really cold here in the UK in the past week or
so). Is it more likely to be a problem with the alternator? Or the battery
(I've got an Exide one that less than a year old and the indicator light on
it is still green). I'm due to drop it into the garage in next week for a
service, should I be OK to drive it as normal until then?

Dan

In article >,
Spack > wrote:
> I have a '93 E36 320i SE, and yesterday I noticed the battery warning
> light come on while driving. A few seconds later it went off again.
> Parked up, did some shopping, came back, started the car up as normal
> and the light stayed on rather than going out as it does normally,
> although it was very faint and kept flickering. A few minutes later it
> went off again. It seems to come and go, driving to work this morning
> it popped up again. I haven't got a voltmeter so I can't dig around
> testing various parts of the charging circuit, any ideas what I should
> be looking for?

Your nearest Maplin, etc? A basic DVM can be had for a couple of pounds
these days. Or check out Ebay for other better specced bargains.

--
*If you remember the '60s, you weren't really there

Dave Plowman London SW
To e-mail, change noise into sound.

"Spack" > wrote in message
. ..
> I have a '93 E36 320i SE, and yesterday I noticed the battery warning
light
> come on while driving. A few seconds later it went off again. Parked up,
did
> some shopping, came back, started the car up as normal and the light
stayed
> on rather than going out as it does normally, although it was very faint
and
> kept flickering. A few minutes later it went off again. It seems to come
and
> go, driving to work this morning it popped up again. I haven't got a
> voltmeter so I can't dig around testing various parts of the charging
> circuit, any ideas what I should be looking for? Is it possible some damp
is
> causing a short? (it's gotten really cold here in the UK in the past week
or
> so). Is it more likely to be a problem with the alternator? Or the battery
> (I've got an Exide one that less than a year old and the indicator light
on
> it is still green). I'm due to drop it into the garage in next week for a
> service, should I be OK to drive it as normal until then?
That light is supposed to go out whenever the alternator voltage exceeds the
battery voltage. So, you should focus on the alternator and the wiring
between it and the battery.
Jim

"Spack" > wrote in message
. ..
> I have a '93 E36 320i SE, and yesterday I noticed the battery warning
light
> come on while driving. A few seconds later it went off again. Parked up,
did
> some shopping, came back, started the car up as normal and the light
stayed
> on rather than going out as it does normally, although it was very faint
and
> kept flickering. A few minutes later it went off again. It seems to come
and
> go, driving to work this morning it popped up again. I haven't got a
> voltmeter so I can't dig around testing various parts of the charging
> circuit, any ideas what I should be looking for? Is it possible some damp
is
> causing a short? (it's gotten really cold here in the UK in the past week
or
> so). Is it more likely to be a problem with the alternator? Or the battery
> (I've got an Exide one that less than a year old and the indicator light
on
> it is still green). I'm due to drop it into the garage in next week for a
> service, should I be OK to drive it as normal until then?
>
> Dan
>
>

I agree with Jim, the suspect is the alternator. If there was trouble with
the battery, you would experience cranking issues, if the cranking is OK,
and the light is coming on, I would be looking towards the alternator as the
source of the problem. If you do nothing, eventually the battery will fail,
and you will be left stranded.

Thanks all. I think even if I had a DVM, I'd still have to work out what to
look for :\

The alternator is what I suspect is failing, but I was hoping it wasn't that
as I remember when the one on my last car went and I got stuck. Driving home
this evening I think I could hear a very faint whirring noise when the light
was off, and I'm pretty sure none when it was on, I'm guessing that the
whirring is the alternator spinning when it's running (albeit sounding like
it's ready to die). I'm going to try and get the car into the garage
earlier, failing that I might have to see about borrowing the missus' car,
although I'm not happy about driving a Ford Ka round after getting so used
to my somewhat larger car :|

Dan

In article >,
Spack > wrote:
> Thanks all. I think even if I had a DVM, I'd still have to work out what
> to look for :\

It should come with basic instructions.

You simply set it to a voltage reading more than 12 - probably 20, or with
a better one it will auto range.

Then connect it across the battery - positive to positive, negative to
negative. Measure the voltage with the engine stopped. A fully charged
battery will read something like of 12.5 - 13 volts. Start the engine and
leave running for a few minutes. The voltage should then read 13.8 - 14.00.

--
*Snowmen fall from Heaven unassembled*

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" > wrote in message
...
> In article >,
> Spack > wrote:
>> Thanks all. I think even if I had a DVM, I'd still have to work out what
>> to look for :\
>
> It should come with basic instructions.
>
> You simply set it to a voltage reading more than 12 - probably 20, or with
> a better one it will auto range.
>
> Then connect it across the battery - positive to positive, negative to
> negative. Measure the voltage with the engine stopped. A fully charged
> battery will read something like of 12.5 - 13 volts. Start the engine and
> leave running for a few minutes. The voltage should then read 13.8 -
> 14.00.

Well it's moot now - the car never made it home from work. Luckily it's just
round the corner from a BMW specialist, so I'm going to try to get it sorted
out tomorrow.

Dan