Odd electrical symptoms

EGTE · 31 Oct 2016

Hi guys,
Can you give me some ideas about an electrical fault I had recently?

The "Generator/Battery Fault" red warning light came on during a long (200-mile) trip. Initially it came and went, but now it stays on (and the warning is announced every once in a while, like 10-15 minutes, as well). The voltage fluctuated between 10-12 volts for a while, but after 20 minutes it sat just below 14 volts (on the motorway and at idle) the whole time.

The car was left (airport car park, no power on car) for 5 days, started absolutely fine and drove me the 200 miles back with no symptoms, other than the red light and 14 volts.

I have now put my CTEK on the car and it's saying the battery is fully charged, so I don't think it's that.

Anyone any ideas? Could the alternator be on the way out? Anything else to check?

Thanks in advance for any advice.

Shurv · 31 Oct 2016

Sounds like alternator. If a cell on the battery has died, it could still read full on a C-Tec, but not be man enough to power the car, ie, what's left of the battery is OK, but you can't tell if you have a whole battery left ( if that makes any sense).
Get it checked out before the car becomes immobile.

EGTE · 31 Oct 2016

Thanks, Shurv.

I'm taking it to be looked at on Wednesday, but wondered if anyone else had had similar.

Cheers.

deMort · 31 Oct 2016

A strange one to check which ive only seen once and on a C4 .. if you dont have a C4 then this isnt relevant .. the main battery lead can come disconnected by the gearbox and rub through on the center prop doughnut , it causes random generator warnings.

If not a C4 then alternator fault i would guess at .

EGTE · 31 Oct 2016

Thanks, Demort.

It's a C2, so it's helpful to narrow things down.

Cheers.

arry · 31 Oct 2016

Similar to mine by sounds of it

http://www.911uk.com/viewtopic.php?t=112115&start=0&postdays=0&postorder=asc&highlight=

Voltage regulator so it seems although I still haven't entirely confirmed as I've not been able to drive car far enough yet - but so far no gremlins.

Not a particularly difficult job to do in terms of technical ability but it's a bit fiddly.

Pro tip - eurocarparts charge about 10 quid more for the Bosch alternator but have a lower surcharge in case you snap the bracket boshing the press fitting about.

Delanor · 31 Oct 2016

The voltage gauge shows the alternator output voltage if its fluctuating between 10-14 volts then its the alternator either the brush pack/voltage regulator or Diode pack is worn.

The brush pack, slip ring and bearings are all replaceable or just replace the alternator.

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Del.

EGTE · 1 Nov 2016

Thanks, everyone; very useful info.

jezgreen911 · 2 Nov 2016

I was getting some voltage fluctuation last winter, I replaced the voltage regulator and all was good again :thumb:

EGTE · 2 Nov 2016

Yes, I think that's the way to go; get the alternator (regulator) rebuilt.

Thanks all.

Odd electrical symptoms

EGTE

Sao Paulo

Shurv

Mexico City

EGTE

Sao Paulo

deMort

Monaco

EGTE

Sao Paulo

arry

Sao Paulo

Delanor

Nurburgring

EGTE

Sao Paulo

jezgreen911

Hockenheim

EGTE

Sao Paulo

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