Hello forum! 

 

Yesterday, while driving my fabia the battery indicator on the cluster turned on and the beeper sounded. After a while the engine died. The battery was discharged! 

I started the engine with a booster and measured the voltage and the reading was 13.8 volts. So, the battery was charging. After a while, at the test drive the indicator turned on again, the voltage soon dropped and the engine died again. Jump starting the engine again, the alternator charged the battery for few minutes and then stopped. The same happens again and again. Any ideas? 

@makymak - When you switch the ignition on, does the battery light come on or not?

Yes, it lights. I guess it's not the signal wire (blue). 

OK, next idea is does the alternator (not just the pulley) actually turn?

Take the regulator/brushpack off the alternator and measure the brush length.  How many miles has the car done?

@KenONeillI will check it!

 

@WinoThis is the first thing I thought. But I couldn't check it since I was in a hurry to leave for the weekend (I was lucky it failed very close to my house and I used the other car). At a glance, it looks like there is no way to take off the regulator without removing the whole alternator. The exhaust pipe leaves no room (1.4 16V). 

Yep, alt will have to come off first.

OK! Thank you. I'll try on Monday. If I will be able to take it off I will replace it anyway. It is a cheap spare. I will ask the previous owner if he has replaced it but I guess no. The car has 230k kilometers on the clock, so it is its time to go... I hope it is not too difficult to take the alternator off. 

You will probably find that after you take the bolts out, the alternator will still be quite stiff to move, so you will need to try to ease the fixing points away from the bracket, doing that will push the spacers back a bit then it will lift off, that is what I discovered when I needed to replace the alternator on a 2009 Ibiza 1.4 16V.

Thank you! At this time the first thing I have to find out is how the belt tensioner will be released. I think it should be a very easy task and no special tools will be necessary. Google is a friend so when the time comes I will do my homework! 

13.8V is too low for a 1.4 16V, it should be 14.4V.

Tensioner is spring loaded and easy to release the belt using a 16mm spanner on the centre bolt.

The alternator is out. The regulator has been changed again with an aftermarket. So, I don't have the oem part number to buy a replacement. The aftermarket has it's own number but there was no luck using it to find the correct part. So, my only choice is to buy the original one from an authorized dealer at a very high price. 

Does the alternator have a VW group part number on it?

 

No, Wino! This could be very useful for me but there is no label. The alternator AFAIK is the oem one (as said by the previous owner who had the car from new).

What year is the car, and does it have air conditioning?

 

12/2000 and yes, it has a/c.

Manual gearbox or automatic?

 

If manual the alternator was probably originally 037903025F (version 15 in first table) and if automatic, probably 036903024D (version 25 in first table) here https://skoda.7zap.com/en/cz/fabia/fab/2002-225/9/903-903000/

If you scroll all the way down to the final table, with the individual parts, voltage regulators are item 4, and the 'note' column has numbers that match the version numbers from the first table.

So for manual gearbox, alternator 037903025F (version 15), the voltage regulator that suits should be 070903803B.

For auto, alternator 036903024D (version 25), the voltage regulator should be 038903803EX.

 

That's all to the best of my knowledge, and assumes that the alternator you have is the factory-fitted one, or an exact equivalent.

 

It may be better to just buy a whole alternator unless you can find a cheap voltage regulator that claims compatibility with the relevant number above, and don't mind gambling a little.

 

Edited 27 May, 20197 yr by Wino

I too would replace the entire alternator at 230k, especially since the brush pack has already been replaced once.

Finally, everything went smoothly! Thank you all for the help!

 

@Wino You are a wisdom! Finally, I found the label of the alt. It was on the back cover that I had removed first of all... The part numbers were exactly what you said!

 

@sepulchrave You were right for the voltage. Now, I have steadily 14.4 volts.

 

One thing I noticed is that now, at idling the tacho is nailed. Before the replacement it was flactuating a bit. 

13 hours ago, makymak said:

.... flactuating a bit...

 

Is that where it makes a noise like a fart?

2 hours ago, vindaloo said:

 

Is that where it makes a noise like a fart?

Yeah! Docs say farting is a good sign of health! 

 

*fluctuating a bit*