Alternator?

D

Dale Clarke

Guest

• Jan 19, 2006

• #1

Land Rover Discovery 1995 tdi

Can anyone help?
Original fault was that the battery light on the dash was glowing. Few days
later the light stayed on so the alternator was replaced. Four weeks later,
we noticed the rev counter was irratic and was 2 or 3 thousand revs plus,
and more when lights or indicators used. Every now and then the battery
light comes on and the rev counter doesn't register at all. After a
re-start, everything is back to normal. I still suspect the alternator but
my mate who does some car jobs seems to think I need an auto electrician.
Before I go to the expense of this, I thought I'd see if anyone had had a
similar fault before or had any opinions on the matter. Please let me know.

Please reply to news group.

 

A

Austin Shackles

Guest

• Jan 19, 2006

• #2

On or around Thu, 19 Jan 2006 17:39:27 GMT, "Dale Clarke"
<[email protected]> enlightened us thusly:

>Land Rover Discovery 1995 tdi
>
>Can anyone help?
>Original fault was that the battery light on the dash was glowing. Few days
>later the light stayed on so the alternator was replaced. Four weeks later,
>we noticed the rev counter was irratic and was 2 or 3 thousand revs plus,
>and more when lights or indicators used. Every now and then the battery
>light comes on and the rev counter doesn't register at all. After a
>re-start, everything is back to normal. I still suspect the alternator but
>my mate who does some car jobs seems to think I need an auto electrician.
>Before I go to the expense of this, I thought I'd see if anyone had had a
>similar fault before or had any opinions on the matter. Please let me know.

check the belt is OK. Check connections on the back of the alternator. If
these are all sound, then hunt the receipt 'cos the alternator is dud.

If it's a 200TDi, then it sounds like a slack belt.

Oh, and check the earth strap on the alternator and the alternator mounting
for security.
--
Austin Shackles. www.ddol-las.net my opinions are just that
"Pereant qui ante nos nostra dixerunt"
(confound the men who have made our remarks before us.)
Aelius Donatus (4th Cent.) [St. Jerome, Commentary on Ecclesiastes]

 

L

Lee_D

Guest

• Jan 19, 2006

• #3

"Dale Clarke" <[email protected]> wrote in message
news:[email protected]...
> Land Rover Discovery 1995 tdi
>
> Can anyone help?
> Original fault was that the battery light on the dash was glowing. Few
> days
> later the light stayed on so the alternator was replaced. Four weeks
> later,
> we noticed the rev counter was irratic and was 2 or 3 thousand revs plus,
> and more when lights or indicators used. Every now and then the battery
> light comes on and the rev counter doesn't register at all. After a
> re-start, everything is back to normal. I still suspect the alternator
> but
> my mate who does some car jobs seems to think I need an auto electrician.
> Before I go to the expense of this, I thought I'd see if anyone had had a
> similar fault before or had any opinions on the matter. Please let me
> know.
>
> Please reply to news group.
>
>

Rev counter picks up it's signal from the alternator. I'd suspect your new
alternator. If it's under warantee then take it back. If not then I got mine
rebuilt for around £35 at a rebuilder (ring a local auto elctrican they
should point you in the right direction). Auto sparky won't be cheap.

Lee D

 

D

Dave Liquorice

Guest

• Jan 19, 2006

• #4

On Thu, 19 Jan 2006 19:06:14 +0000, Austin Shackles wrote:

> check the belt is OK. Check connections on the back of the
> alternator. If these are all sound, then hunt the receipt 'cos the
> alternator is dud.
>
> If it's a 200TDi, then it sounds like a slack belt.
>
> Oh, and check the earth strap on the alternator and the alternator
> mounting for security.

Good stuff but if the basic power system of the vehicle was stuffed
I'd expect more than just the battery light and rev counter playing
silly Bs. What happens when you turn the headlights on during tickover
then rev up is there a noticeable increase in brightness? When ticking
over and you put the heated rear screen on does the engine note/revs
change?

How "electronic" is the rev counter? Is there a dodgey multiplug on/in
the dash wiring?

--
Cheers [email protected]
Dave. pam is missing e-mail

 

R

Richard Brookman

Guest

• Jan 19, 2006

• #5

....and Lee_D spake unto the tribes of Usenet, saying...


> "Dale Clarke" <[email protected]> wrote in message
> news:[email protected]...
>> Land Rover Discovery 1995 tdi
>>
>> Can anyone help?
>> Original fault was that the battery light on the dash was glowing. Few
>> days
>> later the light stayed on so the alternator was replaced. Four weeks
>> later,
>> we noticed the rev counter was irratic and was 2 or 3 thousand revs
>> plus, and more when lights or indicators used. Every now and then
>> the battery light comes on and the rev counter doesn't register at
>> all. After a re-start, everything is back to normal. I still
>> suspect the alternator but
>> my mate who does some car jobs seems to think I need an auto
>> electrician. Before I go to the expense of this, I thought I'd see
>> if anyone had had a similar fault before or had any opinions on the
>> matter. Please let me know.
>>
>> Please reply to news group.
>>
>>
>
> Rev counter picks up it's signal from the alternator. I'd suspect
> your new alternator. If it's under warantee then take it back. If not
> then I got mine rebuilt for around £35 at a rebuilder (ring a local
> auto elctrican they should point you in the right direction). Auto
> sparky won't be cheap.
> Lee D

Remove, clean and make secure the wire to the back of the alt (terminal W?)
first - that's where the rev counter picks up the signal, and these wires
often corrode and get loose. Alternator itself could be fine.

--
Rich
==============================

Time flies like an arrow. Fruit flies like a banana.

 

V

Vincenzoni Attilio, Esq.

Guest

• Jan 20, 2006

• #6

"Dale Clarke" <[email protected]> ha scritto nel messaggio
news:j9Qzf.2852


> we noticed the rev counter was irratic and was 2 or 3 thousand revs plus,
> and more when lights or indicators used. Every now and then the battery
> light comes on and the rev counter doesn't register at all.

These are sign of sloppy cabling from the new alternator. I had same
problems with mine, when "it was young". Had to tighten cable fixing nuts
beyond specs, in order to have the rpm counter give stable readings. give it
a try.

 

V

Vincenzoni Attilio, Esq.

Guest

• Jan 20, 2006

• #7

"Dave Liquorice" <[email protected]> ha scritto nel messaggio

> How "electronic" is the rev counter?

Fully, it has a servo motor who actuates an indicator needle, and responds
to a train of pulses coming from the alternator.

The faster the engine is running, the more frequent the pulses, the greater
the angular deviation of the needle. Any instability of the indicator comes
from the train of pulses not coming in regularly, possbly from a wimpy
connection.

I even purchased a spare rev counter before eventually fixing the cable
issue.

As for lights brightening when engine revs up: this comes from a
less-than-fully charged battery. At low revs it is the battery who feeds the
lights (say, at 11 V). When the engine revs up, the alternator puts out a
full 14 V - they are fed to the battery and to the lights, inversely to the
internal resistance of battery and lights. The lights now get a higher
tension and brighten up.

 

G

Graham Carter

Guest

• Jan 20, 2006

• #8

> Remove, clean and make secure the wire to the back of the alt (terminal
W?)
> first - that's where the rev counter picks up the signal, and these wires
> often corrode and get loose. Alternator itself could be fine.
>
> --
> Rich
> ==============================
I second that. I had major problems with strange rev counter readings, and
after 4 attempts, dealer finally replaced spade connector on alternator
cable. No problems since then.

Cheers!
Graham

 

D

Dave Liquorice

Guest

• Jan 20, 2006

• #9

On Fri, 20 Jan 2006 11:56:16 +0100, Vincenzoni Attilio, Esq. wrote:

>> How "electronic" is the rev counter?
>
> Fully, it has a servo motor who actuates an indicator needle, and
> responds to a train of pulses coming from the alternator.

I live an learn.

> As for lights brightening when engine revs up: this comes from a
> less-than-fully charged battery. At low revs it is the battery who
> feeds the lights (say, at 11 V). When the engine revs up, the
> alternator puts out a full 14 V

Well a properly working alternator will and one without any relatively
high impedance bits in it's wiring. If the lights don't brighten with
revs I'd be concerned that the alternator or its wiring has something
not quite right with it. Hence suggesting it as a basic test.

The step in brightness on the DII on a cold dark morning in full
defrost mode and full lights is quite hefty and doesn't happen until
something over 2000rpm. First time it did it I thought I was seeing
things... That is a pretty cruel test though, with heated rear and
front screens on (2 x 45A of fuses for the front screen), the blower
flat out and main beam.

--
Cheers [email protected]
Dave. pam is missing e-mail

 

S

SpamTrapSeeSig

Guest

• Jan 20, 2006

• #10

In article <[email protected]>, Graham Carter
<[email protected]> writes
>> Remove, clean and make secure the wire to the back of the alt (terminal
>W?)
>> first - that's where the rev counter picks up the signal, and these wires
>> often corrode and get loose. Alternator itself could be fine.
>>
>> --
>> Rich
>> ==============================
>I second that. I had major problems with strange rev counter readings, and
>after 4 attempts, dealer finally replaced spade connector on alternator
>cable. No problems since then.

Indeed, and not just that but also check the earthing, to the instrument
cluster as well as the main strap. It may be corroded, which can make it
intermittent and/or add noise which will cause funnies.


Regards,

Simonm.

--
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SIMON MUIR, BRISTOL UK www.ukip.org
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