Fabia II battery not charging, but no warning light?

[peteonimac]

HELP!

 

My Fabia II Greenline, which is only 4½ years old and has 61,000 miles on the clock, is not charging the battery.

 

 I've done the following checks and need advice!

 

1. Alternator warning light comes on as normal when ignition is switched on and goes out when engine starts.
2. Using a multimeter at the battery and alternator positive feed, the voltage does not go up when engine is running.
3. When the engine is off the voltage reading at the battery and alternator live feed are the same, indicating that the connection between the alternator and battery is good. 

It is most confusing that the Alternator light does not come on when the Alternator is clearly not charging up the battery.

 

If I disconnect the alternator regulator, should the alternator warning light come on when the engine is on. If it does come on, I assume the problem is either in the alternator generator side or the ECU.

 

I would like to check the continuity of the blue wire connected to the alternator regulator, but I can't trace it to the other end. There is only one wire to the regulator so I assume the regulator has a negative earth return. I guess another way of checking the blue wire is to  see if there is power at the regulator connection end. What voltage reading should I get when the engine is running?

 

I'm guessing the blue wire might connect to the Engine Control Unit and I fear that it might lie at the cause of this problem?.

 

Does anyone know what Skoda are doing to fix the emissions software? They have said that my Fabia II requires modification, so does this involve  an ECU change, because if it dies, this may save me the expense of an ECU change now?

 

At the moment I'm having to put a mains battery charger on every day and keep car journeys to a minimum.

Edited 15 December, 2015 by peteonimac

[peteonimac]

I have booked a diagnostic check at my local Skoda dealer for next week, but it's £84 and I'll need to get it to Inverness for the day, so I'm hoping for some guidance before then   

[peteonimac]

I've just disconnected the blue regulator wire from the alternator while the engine was running and the red battery warning light has still not come on! Under what circumstances should this light come on and is it the ECU that controls it? 

 

Not that I'm paranoid, but I seem to be having a forum conversation with myself here! As Pink Floyd said "Is there anybody out there"

 

:think:

Edited 15 December, 2015 by peteonimac

[Breezy_Pete]

What voltage are you seeing across the battery before starting, and when the engine is running? If the battery is very sick, it may be pulling down the alternator output voltage at idle revs due to the high charge current being pulled. Does the voltage go up if you hold the revs at say 2000-2500?

 

The blue wire is, I think, the exciter that gets the alternator going initially, by supplying the current to get the magnetic field started. Once the alternator starts generating power, it's no longer required, the alternator 'feeds itself' that current. It may also have a role monitoring the alternator's output voltage, if that goes low enough, the light should come on (not sure of exact number, sorry).  It is probably fed by the Body Control Module in the cabin, or possibly by the instruments module behind the clocks; I don't have Mk2 wiring diagrams unfortunately.

 

With engine off, but ignition on if you measure the voltage at the alternator end with it connected you'll see a low voltage (and the charge light on). If it is disconnected from the alternator though, you should see roughly the same as battery voltage, or a little lower (and the charge light off).  The fact that you see the battery light come on with ignition suggests that this wire is intact, but it might just be so frayed somewhere that it can't carry enough current to kickstart the alternator. Doubt it, but possible.

[2ndskoda]

Firstly -  a 4 and a half year old battery?? - first area of suspicion.  I cannot see from your post if it is  the original battery?? Have a simple drop test on the existing battery without delay.

 

As Wino has suggested - put a voltmeter directly across the battery, and when running at 2000/2500rpm approx - if you have a reading of approx 14.3v - then your alternator output is about right.

 

Make these simple checks  first, before overcomplicating what might be a simple issue to overcome.

Good luck

[jonro2009]

I have no idea about batteries and alternators etc so can't comment on that, sorry

I would say that at 4.5 years old the warranty is out so I would not be taking it to AC in Inverness even if I lived next door! Try Bitz in Nairn or even pedigree motors in Forres for a cheaper diagnostic?

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[peteonimac]

Wino Quote: "What voltage are you seeing across the battery before starting, and when the engine is running? If the battery is very sick, it may be pulling down the alternator output voltage at idle revs due to the high charge current being pulled. Does the voltage go up if you hold the revs at say 2000-2500?"

 

Thanks Wino, but the voltage stays the same no matter what the revs are, or whether the engine is running or not 

Edited 16 December, 2015 by peteonimac

[peteonimac]

With engine off, but ignition on if you measure the voltage at the alternator end with it connected you'll see a low voltage (and the charge light on). If it is disconnected from the alternator though, you should see roughly the same as battery voltage, or a little lower (and the charge light off).  The fact that you see the battery light come on with ignition suggests that this wire is intact, but it might just be so frayed somewhere that it can't carry enough current to kickstart the alternator. Doubt it, but possible.

Thanks Wino, something to consider if all else fails1

[peteonimac]

Firstly -  a 4 and a half year old battery?? - first area of suspicion.  I cannot see from your post if it is  the original battery?? Have a simple drop test on the existing battery without delay.

 

As Wino has suggested - put a voltmeter directly across the battery, and when running at 2000/2500rpm approx - if you have a reading of approx 14.3v - then your alternator output is about right.

 

Make these simple checks  first, before overcomplicating what might be a simple issue to overcome.

Good luck

Thanks 2ndSkoda, it's a new battery.

I'm coming to the conclusion that it's the Alternator at fault rather than wires/cables connected to it, or other components controlling it.

[Breezy_Pete]

What voltage is it staying at?!

[peteonimac]

Thanks Jonro2009,

I had a 3 year service plan with Arnold Clark and it was in there for one of them when I asked them to check out a slow tyre leak. I was told they could not find anything wrong, so I took it to a garage in Forres and they spotted a nail in the tyre within a few seconds of looking at it! Also got them to put a tow bar on it when it was delivered,  but they fitted the electrical socket upside down because them had not fitted the mounting bracket the right way round. It was a dark day when AC took over the old Delmore Skoda dealership on Carsgate Road.

Edited 16 December, 2015 by peteonimac

[peteonimac]

Wino,

 

It stays at whatever the battery voltage is, 12ish volts if it's getting a bit low or 13ish if I've charged it up.

 

I think it is the Alternator that needs changing.

Edited 16 December, 2015 by peteonimac

[jonro2009]

Indeed, I never dealt with Delmore but heard good things. I've used Bitz a few times, got to love the gravel grannies! They have been very good, also used the ford garage in Nairn, the name escapes me though. I've had to get SUK involved with AC twice now, the service girls are great but it ends there unfortunately

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[Breezy_Pete]

Wino,

 

It stays at whatever the battery voltage is, 12ish volts if it's getting a bit low or 13ish if I've charged it up.

 

I think it is the Alternator that needs changing.

Fair enough. 

[peteonimac]

I phoned Bitz and they were able to tell me that the blue exciter wire coming from the alternator changes to a violet and white at the next connector, so I put the Skoda on ramps and I took the plastic engine compartment, underside splash guard off to see if could trace the wire and check for damage and continuity. Within seconds of gaining access to the underside of the engine I found the said connector which had a violet and white wire chaffed right through, very close to the connector. This is a ridiculously thin wire and it looks like the sleeving the wires run through flaps around and chaffs against the wires. Poor design or installation of the sleeving to allow it to chaff against the wires, a longer sleeve, or tie-wrapping the end would have prevented this. Here is a photo:

Chaffed wire 19Dec15 by Pete Mitchell, Scotland, on Flickr

 

​Not much wire sticking out of the connector, but managed to solder a patch wire to bridge the gap, then fit heat shrink over as insulation. Not pretty, but it's solved the problem and the alternator is charging the battery again. Here is the patch wire photo:

Chaffed Wire Repair 19Dec15 by Pete Mitchell, Scotland, on Flickr

 

Here is a photo to help others locate the connector on the underside of the engine (notice the tie-wraps I have put on the sleeves to prevent further chaffing):

Chaffed wire location 19Dec15 by Pete Mitchell, Scotland, on Flickr

 

I hope this helps anyone with the same problem?

Edited 21 December, 2015 by peteonimac

[jonro2009]

Bitz all the way! Glad they could help and you got it fixed

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[2ndskoda]

Well done, and thanks for reporting back. That is a very useful bit of information.