Replacing the alternator (Generator?) in a Fabia

[TroelsDK]

Hi.

 

New member here. 

Disclaimer: I have very limited experience with fixing cars, but I've worked in electrical engineering for the last 20 years, and is quite skilled in fixing everything else - so hopefully thats enough for this.

 

I have an old Fabia with approx 260.000 Km on it.: SKODA FABIA (6Y2) 1.2 (40 KW / 54 HK)

Really beginning to show its age, but runs fine and I would really like to keep it going for 1-2 years more.

 

The Battery light is starting to light up more and more. 

I was told that a "quickfix" was to wack the alternator gently with a hammer and listen for the motor to slow down a little.

This method has been very effective for the last year, but now its required at least once a day and I need to wack hard...

 

Based on this, I'm pretty sure that the problem is with the alternator and I've been tempted to try, to fix it my self.

 

The car is so old that, even If I completely wreck it, I can live with it.

The offer from a mechanic is 4000-5000Dkr (~550Eur) and I'm not sure the car is worth that much....

 

So, what are my options here? lacking experience, I think this is the plan: 

1. Test if the alternator can be removed from the car with my limited tools and skills ( Have found a YT-video, and it looks simple)
2. Take out the alternator and look for loose connections or mechanical parts that could be stuck (anything the aligns with the "hammer-repair-method")
3. If no apparent fix is obvious, order a new alternator online and try to mount that (looks like I could get an Bosch-part for below 200Eur)

 

Does that sound totally wrong?

 

Regarding new parts: I've been looking at AutoDoc and they list many different options when I enter the licence plate. 

Some of the listed parts are slightly different. 50mm vs 56mm pulley for example. Would anyone know what the critical parameters are?

 

Thanks in advance, and sorry for my complete lack of correct terms 🙂

 

Kind Regards Troels

Edited 16 May by TroelsDK
bad spelling

[Paws4Thot]

@TroelsDK - Replacing the alternator or even "servicing" it seems unnecessary until you've proved the load sense wire isn't coming loose.

[TroelsDK]

Hi.

 

Thank you for the input. I have no idea what a "load sense wire" is. (will try some googling)

 

Des it make sense that the problem can be solved everytime by tapping the alternator? - does that wire go directly to the alternator (preliminary googling gives me hits around starter-motor?)

 

22 minutes ago, Paws4Thot said:

@TroelsDK - Replacing the alternator or even "servicing" it seems unnecessary until you've proved the load sense wire isn't coming loose.

 

 

Kind regards Troels

[TroelsDK]

One additional information:

 

Everytime I have had this problem the battery-symbol in the dashboard lights up (red).

I will stop the car, leave the engine running and tap the alternator. Cant remember is the battery-symbol goes out immediately after tapping or by next motor-start, - but it does go out. 

BUT, i have no way of telling whether the symbol comes on as soon as the fault is present or only when the battery-voltage is low, - or something else?

 

Kind regards Troels

[rum4mo]

Tapping the alternator might be freeing up the small carbon brushes that are either sticking in their holders due to a build up of carbon dust, or the same issue and they have worn down so are now too short to be useful.

I due to the huge cost difference, when the alternator on my older daughter’s 2009 SEAT Ibiza 1.4 went badly faulty - stopped charging, I gambled on buying a reconditioned Bosch one same O/P but with a slightly small pulley diameter - that worked out okay for that car.

On your alternator the brushes are probably part of the regulator pack which can easily be replaced, you could hope that the slip rings that they connect with when in use are still serviceable. Normally it is shaft bearings that out an alternator out of use, but maybe your ones are still okay.

[TroelsDK]

Hi.

 

Spend an hour looking/poking/screwing at the alternator and now its out of the car, - so no way back now 🙂

 

It looked fine and turns very smoothly so I proceeded to take the the thing apart.

 

A screw holding the plastic cover broke, but I assume its less important. 

Next I removed a black part and that revealed the brushes (pure luck in my disassembly process)...

 

The top slip-ring was very dark, but a light scrub made it look as shown in the picture.

The top brush appears to be more worn than the lower. (maybe hard to see in the pictures

 

Im assuming that the brushes are OK for a little more?

 

Both brushes mowe freely, but I would guess that the top brush has a hard time making prober contact.

It dosnt look like its possible to move the brushes, but I might try anyways, - nothing to loose.

 

Please have a look at the pictures and tell me what you think.

 

I Hope the brush-part-thingy is available as a sparepart?

 

Kind regards Troels

[Warrior193]

The slipring you say was darker than the other possibly indicates that the associated brush was not making proper contact - there does look to be a considerable amount of wear on both sliprings too.

I'd suggest that the old carbon brushes are unserviceable.

Edited 16 May by Warrior193
correction

[Breezy_Pete]

Yeah those brushes, especially one them, are way too short.

[TroelsDK]

Found this on YT: 

 

Looks veeeery close to my model.

 

Apparently it IS possible to change the brushes, - although probably not recommended..

 

I think, I will give it ago, and verify that this IS indeed the rootcause. - before investing in more parts

 

Kind regards Troels

Edited 16 May by TroelsDK

[J.R.]

Easy job and will have it running like new again, the brushes come as part of a new regulator.

 

If you need the car running again while you order the regulator pack you can do as I did which was to free off the brushes and allow them to extend a little further, I think I cut relief grooves in the plastic to allow the braid wire to extend further, it was a long time ago.

 

The bodge intended for no more than a week was still working fine 6 months later when I finally got around to fitting the regulator.

 

Good on you for finding a way to overcome the problem which also diagnosed the fault at the same time!

[TroelsDK]

Feedback: Much to my surprise I got the alternator out with too much trouble. 

(Very pleased with my self, as it was the first time I did anything like that on a car)

 

The drive-belt was a bit tricky as I did not have the prober torx-bit to hold the small pulley thats mounted to spring.

 

I did not have the correct size brushes, but I did have some spare brushes for a makita belt-sander.

With a bit of saw-file-work they fitted fine and was easy to solder.

 

100Km later and the car is running fine(*). - no more battery-symbol-warnings in the dash 

 

*"Fine" as in: that specific problem is gone 😉

 

Thanks for the support.

 

Kind regards Troels