I am having what seems like battery/alternator issues in my Skoda Fabia 1.2 Patrol 2008 and I am trying to get to bottom to issue before starting to replace parts.

 

The problem stared a month ago where sometimes I get a blink of red battery sign on dashboard after I start the car. I didnt thought much but then I started getting this battery sign for longer time once I start the car. I thought maybe something is draining the battery. This being skoda means that some parts always have electricity even when car is completely stopped (the lighter outlet for example). My first thought was glove box as I always thought that light is always on for some reason. I put camera in and saw that even when I close, the bulb is still on. I just removed the bulb and kept on. But I would still get the battery sign after starting.

I went on vacation and my friend started car once and said there was no sign. I came back after 3 weeks and started the car after some freezing temperatures and it started without issues. Still got the battery sign. I kept driving as the battery sign would go away after a while and I kept thinking its because the battery is discharged and the light goes away once its charged enough (seems like I was wrong). What I did observe at that point was then when I did cold starts, there was no light. But if I then stop (like I go to market and park the car for some minutes) and then start again, I get the battery sign.

 

So a few days ago when I got similar behaviour I thought the battery would eventually charge but as I was driving I saw electrical systems slowly fail. First I got ABS sign, then I got handbrake warning, then power steering died and then a few more signs before eventually the car died completely. I was able to park it for the day. Next day I got a multimeter and went with my friend to jump start. I could see that battery was showing something like 11.4V. So we connected hist car and was able to charge. Then we were able to get the car running. The battery sign again showed up again . When running, I checked with multimeter and it was showing 12.6V or something so battery wasnt being charged by alternator. I asked my friend to rev up a little and he reved to 4k-5K RPM for few seconds and then I could see the voltage jump to around 14.4V and the battery sign gone. We were then able to get the car back home. I kept the car running for a while and when I checked the voltage again while running it was showing around 13.8 or 13.9V.

 

Now after that what I have been observing.

1. When I do cold start, I get battery sign but if I rev up enging, it goes away and I could see the battery being charged.
2. When I do a small stop or when I start the car again when the engine is warm, I cannot get the battery to charge no matter how much I rev.
3. Once it start charging and I drive a little, the next day, before starting when I check my battery it shows around 12.8V which seems like battery health is ok.
4. Once the alternator engages, I can drive for hour and it keeps working fine. 

 

What I have done so far, is:

1. Check alternator fuse on battery which seems to be fine
2. Clean battery connector 
3. While running shake battery connectors and alternator connector (what I think it is) and see if battery sign goes away - it does not
4. I can see that alternator is always spinning throuhg belt even when I have battery sign. Not sure if there could be slip or if its slow but looks fine. As I mentioned, once the alternator start charging, I dont see battery sign again until I stop.

 

So I am not sure where to start looking for issue now. I read a few threads here and some of them suggest some wires under the car but the link to those pages have no pictures or the pictures were taken down so now sure what to look for. Any help here would be good before I
start spending.
 

@Ata84 Best suggestions are alternator control wires, or sprague clutch not engaging (if fitted).

Could also be worn brushes in the alternator. It may manage to charge at higher revs on longer journeys but not at start up.

 

47 minutes ago, Paws4Thot said:

@Ata84 Best suggestions are alternator control wires, or sprague clutch not engaging (if fitted).

`How to check if the clutch is fitted. And is there any video or pictures or thread on where these control wires are?

 

1 hour ago, Ata84 said:

`How to check if the clutch is fitted. And is there any video or pictures or thread on where these control wires are?

 

The exciter wire goes from the alternator I think marked L on the alternator to the back of the cluster/battery light (might be blue). There is another marked DFM which I think is a voltage sensor wire that goes to the ECU. The third goes to the battery. Under the car in front of the gearbox theres a few cable joins on a bracket below the starter motor if I remember right. 

Alasdair

2 hours ago, Ata84 said:

`How to check if the clutch is fitted. And is there any video or pictures or thread on where these control wires are?

 

Look at, or post a photo of, the end view of the alternator belt pulley. 

If all you can see is a big nut, you don't have a freewheeling pulley.

 

I don't think the exciter wire can be the problem because when that breaks, the battery light never works at all. The other thin wire is for monitoring only, and doesn't affect charging.

 

I think voltage regulator/brushpack is the most likely problem. 

Yes, sounds like brushes to me.

So I guess getting a new battery wont help in this case. I guess the only way to check brush is to take the alternator out?

Check accross the battery with engine running with multimeter in DC mode. You should get 13.5-14v Change to AC mode on meter to see if there is any reading. If you get an AC reading then the regualtor is probably shot. The fact that you get a spike in voltage when revving does point to worn brushes but worth a quick check before removing alternator.

There is also a very slight possibility that the belt may be slipping?? 

Alasdair

So I got new battery but same issue persists. And now I think whatever was failing has completely failed as I could not get the battery sign to turn off even after reving. 

 

There is no clutch, just pully

 

So either its regulator now or alternator control wires? How can I rule out wire with multimeter or do I have to do visual inspection under car?