Hi,

My Felicia 1,3 from 1996 has stopped charging. I have done some Google research, and narrowed the problem down to the alternator OR (semi-external) regulator.

However, I wonder if I can isolate which of the two is faulty ?  The alternator is still mounted in the car.  Some facts:

Battery fully charged before testing.

When starting engine NO rise in voltage - measuring battery terminals voltage is same as alternator B+ to ground (very small voltage drops both ground and B+)

There is continuity between alternator B+ and lead connecting to battery + terminal => I conclude there is no fuse blown, or anything preventing current from alternator reaching the battery (am I right?)

I have not yet tested if the green wire "bundled" with the thick red + wire also supplies the correct battery voltage - would that be a problem?  As I understand it, 0 volts here would prevent the rotor coils from being magneticed / excited ?  Or am I mixing it up ?

Screwed to the alternator is also a white box which seems to be another rectifier, which nobody mentions the function of - or how it would malfunction... ?

 

Finally I am wondering: is it likely that there is a single break in the stator wiring (or solder connections) - and would a single break prevent the alternator from generating any current at all - even if rotor / excitation and voltage regulator works ?

 

A lot of questions from me - a forum newbie, so be gentle with me :-)

Hello, welcome to the forum. The white box will be a RFI suppressor or surge arrestor - you could try disconnecting it to confirm that is not part of your problem.

Are you able to confirm continuity of the field and armature windings? - checking this this will also rule out an issue with the sliprings and brushes. Most likely your problem will be the regulator. 

Yes, a break in either the stator or armature windings will result in no output, but would think unlikely to be the problem unless the slipring brushes have failed. 

Edited 12 July, 20232 yr by Warrior193
added information

Thanks for your reply.

I have not yet removed the alternator, so I haven't been able to test continuity in windings, etc.

Today I have received a replacement alternator with regulator from a junk yard (approx. 70 £ !), and I will try to test it before removing my original.

Also, as some have pointed out in this forum earlier, it should be much easier just to replace the regulator without having to unmount the alternator?!

 

I have noticed the following:  When starting the engine and idling, the dashboard battery warning comes on - but when I rev the engine it goes off again - but I still only measure approx. 12,5 volt - so it is still not charging!  How can this be explained ?

I did not put a big load on the system - only headlights - do I need to stress it more to provoke charging (if possible), when the battery is full ?

 

Thanks again for your help!

1 hour ago, GrosAffe said:

it should be much easier just to replace the regulator without having to unmount the alternator?!

 

Of course !

2 bolts and it's out then you can make the indpection for the brushes, you can buy new ones and install them.

No need to buy new and expensive parts before it's 100% sure that you need them, i have done the same mistake in the past.

2 hours ago, GrosAffe said:

Thanks for your reply.

I have not yet removed the alternator, so I haven't been able to test continuity in windings, etc.

Today I have received a replacement alternator with regulator from a junk yard (approx. 70 £ !), and I will try to test it before removing my original.

Also, as some have pointed out in this forum earlier, it should be much easier just to replace the regulator without having to unmount the alternator?!

 

I have noticed the following:  When starting the engine and idling, the dashboard battery warning comes on - but when I rev the engine it goes off again - but I still only measure approx. 12,5 volt - so it is still not charging!  How can this be explained ?

I did not put a big load on the system - only headlights - do I need to stress it more to provoke charging (if possible), when the battery is full ?

 

Thanks again for your help!

The issue with the warning light extinguishing when the engine speed is increased suggests that the alternator is outputting just enough to trigger it - but not enough to charge.

Reasonably confident this confirms a fault with the voltage regulator.

Regardless of battery charge state, you should be seeing at least 13.5 volts at the battery terminals when engine is running at more than around 1500rpm

Thanks again !

So I guess my next step is just to try to replace the "semi-external" voltage regulator using the one on my new (used) alternator...

D.FYLAKTOS you write it's just unscrewing the 2 bolts (and unplugging the white "sense" lead...) and  replace it ?

No tricky springs getting loose / lost, and easy to put the brushes back in ?

Of course I can practise on the "new" junk yard alternator...

 

If I need to go to next step of removing the alternator, am I right that on my old model, there are no complicated pulley-drive-train adjusters - it is simply a case of mounting it with the right tension and tightening the nut(s) ?

1 hour ago, GrosAffe said:

Thanks again !

So I guess my next step is just to try to replace the "semi-external" voltage regulator using the one on my new (used) alternator...

D.FYLAKTOS you write it's just unscrewing the 2 bolts (and unplugging the white "sense" lead...) and  replace it ?

No tricky springs getting loose / lost, and easy to put the brushes back in ?

Of course I can practise on the "new" junk yard alternator...

 

If I need to go to next step of removing the alternator, am I right that on my old model, there are no complicated pulley-drive-train adjusters - it is simply a case of mounting it with the right tension and tightening the nut(s) ?

Yes, that looks like the usual 'old school' type of adjuster - usual tension is to allow max of approx. 25mm deflexion when pressing down reasonably hard on longest span of belt run.

1 hour ago, GrosAffe said:

No tricky springs getting loose / lost, and easy to put the brushes back in ?

 

No, just 2 bolts and you remove that aluminium look box with the 14V stamp plus the 2 cables.

An example from other vehicle:

 

When you take it in your hands open it and you will find something like These inside, check for worn signs.

In the "old type" altenators like your this is easy, in modern altenator models this task can not be done except if you go to the repair shop to lift the car high.

Thanks again for your help !!

 

BTW, I have just found this video, that I think is the best I have found yet about troubleshooting the charging, when you know the basic things (mechanical and connections) are ok...   : 

 

It is fixed now !

 

I swapped the regulators and now it charges at approx. 13.5 volts !

I was very lucky the junk yard alternator's regulator was not faulty, and the brushes were not worn down (one was shorter than the other - and both were shorter than my original ones, as my Felicia was only gone 90,000 km in 27 years). So now I have spare brushes and other alternator parts if needed...

 

It feels good to have saved a lot of money not going to a professional repair shop / garage, and fixing it in 10 mins (excluding research and your help!)  🙂

Thanks again, and bye for now...