A few days ago, my battery light started to shine.

 

I have topped of the battery with a external charger.

 

Voltage:

Off: 12.6v

Idle: 12.6v

2000rpm: 13v

The battery light on the dashboard is shining more brightly at 2000rpm than at idle.
 

Voltage regulator broken and need replacement?
Brushes worn out? (Should be unlikely, low milage, only 45000km)

 

I have a 90amp alternator spare, from a 1.6 Felicia with AC. Could this be fitted without problem?
 

 

Thanks in advance!

Yes you need a new regular as running should be 13.8v and as long as you have power steering the alternator will fit I have been running a 120amp one on my air con model off a sdi polo with the help off a grinder...

So which procedure would you recommend? Purchasing a new regulator and replacing that, or fit the 1.6 regulator in the 1.3 engine?

(I do have power steering)

New regulator is not much money.

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If it a 1.3 then new reg as 1.6 alternator will not fit a 1.3

The last regulator I bought cost about £13, my son got his whole alternator replaced (because he was lazy), and it cost him nearly £200.

I was at the local supplier of spare parts this morning, and they seemed to have no clue at all.
Don't think it's that common to purchase spare regulators for felicias here in Sweden.
Is there any good site that delivers to Sweden, or should I just call the closest skoda dealer (100km away) and pay the price for a genuine part?


Also, is all hope out, to fit the 1.6 bosch alternator (90 amps) ? Is this something that can only be done with huge effort?

I'm confused, your profile says 1.6 kombi.. The alternators from the vw engines will not fit the 1300cc skoda engines..

the voltage regulator will cost a lot from the skoda dealer, and they will want the old one back in exchange too, If it was me I would just look on ebay or check out some local breakers yards for a second hand alternator.

Updated my profile now, I have both the 1.6 and the 1.3.
The 1.3 I recently purchased to replace the old one which is nearing retirement age.

There is no hope to force the bosch VW engine alternator into the 1.3 engine?
I called the skoda dealer, and they want 50euro for a new volatage regulator, which is the same price I can get a new alternator from a scrapper. (Allthough the delivery is probably higher on the alternator.)

But is there nowhere that I can order just the regulator for cheaper than 50euro?

I changed my voltage regulator last year on a 1.3. I bought a new one from Skoda, it was about £30. Easy to fit though.

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I bought a new one from Skoda, it was about £30. 

£30? We pay in here the equivalent of £12 for one made in Germany or £5 for one made in China. Those are dealer loco prices. You get even lower prices by ordering online from Czechs or Slovaks. I am always amazed how expensive parts become after passing the Channel...

Edited 6 October, 201312 yr by adurer

£30? We pay in here the equivalent of £12 for one made in Germany or £5 for one made in China. Those are dealer loco prices. You get even lower prices by ordering online from Czechs or Slovaks. I am always amazed how expensive parts become after passing the Channel...

Adurer, do you know somewhere I could order the part online?

Paying 5 euro instead of 50 sounds like a good deal to me.

Also, do I need to remove the alternator from the car to change this thing? Shouldn't it just be to open up the back end and replace the relevant parts? Or am I looking at the wrong place?

Also, do I need to remove the alternator from the car to change this thing? Shouldn't it just be to open up the back end and replace the relevant parts? Or am I looking at the wrong place?

You only need a short flat screwdriver. No need to remove the alternator. Disconnect battery minus first.

 

 

Adurer, do you know somewhere I could order the part online?

Sorry, I don't. I usually don't need to order online, I get the parts from local dealers without having to sell a kidney.

But there are Czech members that know better than I do. In fact it would be a great idea to create a Briskoda e-shop with parts coming exclusively from Czech Republic or Slovakia at lowest prices.

I managed to find a place relatively nearby which sold me the regulator for 23 pounds.
Now I just have to replace it, and I notice that I have no information on how to do this in my Heynes book.

Is this a extremly easy operation, or need I obtain schematics or a manual from somewhere?

Is this a extremly easy operation, or need I obtain schematics or a manual from somewhere?

REMOVE

- Unplug connector 2

- Unscrew two screws 1

- Take out voltage regulator

 

INSTALL

-Reverse operations

 

Edited 8 October, 201312 yr by adurer

The instructions were helpfull.
The process of replacing the regulator was very easy, it took me only 10 minutes in total.

However... After replacing this voltage regulator, my charging light still shines... :(
So probably there is some other issue!

I have not checked how much voltage the generator produces now, since I have my meter at home.

Any ideas what the issue could be? Where should I look next?

If something very obvious didn't happen (loose belt or even no belt ) then I would charge the battery overnight at home and try again next day. How old is the battery? Check negative battery cable connection to chassis (remove, clean, install). Clean battery posts. If still no luck, you either have a faulty bridge rectifier, or bad wiring between alternator pin D+ and dashboard.

I don't think the belt is loose, but I have limited experience and what I would say is firm could be loose.

 

I have charged the battery, but will do so again.

The battery is old, from 2007 or 2008. 

Battery posts I have cleaned, but I have not checked the negative battery cable to the chassis, will do that.

 

Thanks adurer!

Well... looks like the culprit was the battery all this time. But let's give it one last chance. Do a battery load test EXACTLY as described at http://www.youtube.com/watch?v=tsJUuLu1cw0&hd=1. If the battery passes the test you have a faulty alternator and we'll check what's bad with a multimeter.

Edited 10 October, 201312 yr by adurer

I tried with a fresh battery, but I had the same problem.

I watched your video, but I do not have a min/max function on my multimeter.

But I do not see any voltage below 10v with my naked eyes, while starting the engine.

 

From your video, I did find this one though, "Related".

 

And I followed the instructions.

I have now seen that I have a voltage drop of 0.15v, from the alternators positive cable (Is this the D+ pin you spoke of?) to the batterys positive terminal.

I had only 0.01 to 0.04v drop, from the batterys negative terminal, to the alternators chassi.

 

I polished the terminals and the cable-shoes. And I can't see anything that would indicate a cable break between the alternator and the battery.

The positive cable from the alternator also looks perfecly ok.

OK, we're getting closer. I assume you still have 12.6 V (or whatever battery voltage is) at battery terminals, no matter engine rpm.If battery is good, voltage regulator is good, wiring is good, and belt tension is OK (some 1 cm arrow when pushing with your finger), we are left only with a faulty alternator. Let's diagnose it.

 

Now I will have to bore everybody with some theory about how alternators work, to have a clear picture of where we are now. We need (as usual) some photos for a better understanding.

 

The first photo is the wiring diagram of the alternator.

It is important to know that we need a magnetic field in winding 2 ('excitation') of the rotor. The rotor is fixed to alternator pulley, so when it rotates an alternating current is induced in the stator winding 3 which is then rectified by diodes 4 and 5. The more current we feed in winding 2, the stronger the magnetic field of the rotor is, thus the bigger the charging current of the battery will be. The voltage regulator 1 handles this function automatically based on voltage supplied by diodes 6.The excitation current is fed to the rotor by 2 carbon brushes that make contact with copper slip rings on the rotor.

 

The second photo shows the corresponding alternator terminals.

Now you can have a real-life correspondence to wiring diagram.

 

The third photo shows the block of diodes inside the alternator.

Diodes are mounted on 3 separate plates acting as heatsinks. Diodes 4, 5 are the big ones because they need to handle 70A in our case. Diodes 6 are smaller, the excitation current is maximum 3A or so.

 

So now let's see what could be wrong. Well, we sure have a too low voltage at terminal D+ because the battery lamp stays lit. Knowing the voltage regulator is new, that may happen due to (in order of difficulty to repair):

 

- the copper slip rings of the rotor (collector) are very worn or very dirty

- one or more diodes 6 are faulty (open)

- one or more diodes 4 and 5 are faulty (open or short)

- the rotor winding is faulty

- the stator windings are faulty

 

You certainly have to take out the alternator and investigate what's wrong.

Awesome diagrams and pictures adurer, this intrigues me to take the alternator appart instead of lazily just buy a new one.

I did not recieve any answer on the voltage drop between B+ and the battery positive terminal though.
Is this a possible symthom of the alternator not cranking out enough power?
Or is it possible that something between the alternator and the battery steals power when it shouldn't?

I have to drive tonight, but after that, I'll go on and remove the alternator.

Everything Adurer says is correct, BUT he's ignored the posibility of worn-out brushes

No, I didn't ignore that possibility. If you read previous posts you'll see the voltage regulator is new, so... new brushes, right? Trust me, it took me more than half hour to compile the photos & write that reply.

 

I did not recieve any answer on the voltage drop between B+ and the battery positive terminal though.

Is this a possible symthom of the alternator not cranking out enough power?

Or is it possible that something between the alternator and the battery steals power when it shouldn't?

I didn't answer because those are normal readings. You don't need more obvious symptoms than not charging at all and battery light is always lit.

 

I encourage you to disassemble the alternator, clean well with alcohol the copper slip rings and take close up, focused, well lit photos. You may need only find sanding the slip rings. Clean also the block of diodes and measure all of them. Show us photos if you like. Look for overheating or arcing signs on windings. Be methodical and patient, you may end repairing it with minimum costs.

I did manage to get the alternator out of the car tonight. But it wasn't easy... That tensioner gave me huge problems. :(

I did dissasemble the alternator, and started to investigate.
It took quite some time, to realise how the diagram corresponded to reality.

It turns out my alternator had sets of 4 rectifier diods, not 3.

I started to measure the resistance through the diods with the "diod meter" setting on the voltmeter.

This is what I found:

Table is measured from Colum, to row.
I do not know the unit.

 

From\                 To

             Stator    B-   B+   D+
Stator       0        inf    0    471
B-             469    0     469  922

B+            0        inf    0     472

D+            inf      inf    inf    inf

 

It would appear to me, that I have a faulty diod amongst my positive rectifier diods, since there is no resistance between B+ and the Stator (which I would expect to be infinite).
And that it is no resistance between the stator and B+, further indicates that this line is open.

 

Is there some way to measure them individually, without soldering them loose?
What would be the effect, if I found out that one of the diods are faulty, and I simply remove it?

Would I be ok with such a crippled alternator, as long as I don't consume alot of amps?
 

You can't have proper measurement with stator winding connected. You need to unsolder it and fill the table again. I will then answer to your all other questions.

 

PS

I was confused by the fact you have 2 cars in your profile and the spare alternator from VW added to confusion. So what amperage has the alternator you opened? 90A from Felicia 1.6 with A/C and power steering?

Edited 13 October, 201312 yr by adurer