How can I solve this weird electrical problem in my car?

[Karabiner98k]

Hello everyone,

1 month ago my car (Peugeot 406 1.8 16V LFY) had a charging system issue. The alternator didn't charge the battery and the battery warning light stayed on.
The alternator diagnosed as faulty. The repairman told me that the Brushes are worn but you must replace the whole voltage regulator as a whole and not just the brushes.

The original alternator on the car was made by Bosch and I searched a lot to find a used voltage regulator with solid brushes. He fitted the voltage regulator and fitted the alternator on the car.

I thought the problem was solved but it was just the beginning of trouble! My car had been sit unused for about 2 weeks and when I wanted to start the engine the battery was weak. I jump-started my car but after 5 minutes the engine died. I turned it on and increased the throttle a bit (about 2000 RPM) and the engine stayed on. I tested the battery voltage with the engine running and it was 17.2 volts!!!! I took the car for a spin and it dropped to 14.9 volts! Still too high. The car didn't behave normally as well! The engine has a fast idle (about 1500 rpm). I don't know what it has to do with charging system!

Today when I started the car the battery warning light appeared again and battery voltage was 12.3 (no charging!). I shut off the engine and started it again and the voltage was 17.2 volts and the idle was about 2000 RPM! Sometimes the idle dropped to 800 and the car behaved normally but soon the fast idle would return!

It is driving me crazy! I don't know why these things happen! Maybe the voltage regulator is faulty but what does it have to do with fast idle?!

 

[KiwiRob]

buy a new car.

 

[Giannis]

My understanding is that you have a faulty voltage regulator. I'd suggest you reinstall your old one and see if anything changes.

The idle issue should be connected to the voltage regulator. A faulty voltage regulator driving the alternator to overcharge the battery will increase the idle, if at idle speed you don't produce enough juice. Those high and low voltages don't really make sense, unless you suppose you have a problematic voltage regulator. Then everything makes sense.

buy a new car.

It is my understanding that although most people do want to buy a new car when the existing one has some sort of a problem, they can't always afford to change cars like shoes. So, that's just worthless advice.

 

[CrunchSlaughtered]

It's the voltage regulator for sure. And also there is a way to change the brushes. The producers make it as hard as possible, so that the customer is forced to by a new voltage regulator instead of only changing the brushes. Anyway, it is possible to change the brushes on almost all Bosch and Valeo alternators, but you will never see it officially. Also if you search for second hand parts the cheaper and safer way is to by a whole alternator together with the regulator, than only the regulator.

 

[Karabiner98k]

Thanks a lot for your answers.
I have been told not to change the brushes because they say by doing this, it will work for a few days and stops working again.
The price of a new alternator is sky high. It would be helpful if there was a way to determine the condition of the voltage regulator before buying. It seems the one I bought is faulty.
I have also been told that high voltage damages electronic devices, sensors and engine ECU. How much does it cost to replace all of them?

 

[CrunchSlaughtered]

Thanks a lot for your answers.
I have been told not to change the brushes because they say by doing this, it will work for a few days and stops working again.
The price of a new alternator is sky high. It would be helpful if there was a way to determine the condition of the voltage regulator before buying. It seems the one I bought is faulty.
I ha...

The new set of brushes will last about 200 000 km, if they are original. If they are not original and are harder they will wear fast the copper bush of the alternator and it is much harder to be changed, if they are softer they will wear for 30 000- 50 000 km. Otherwise the high voltage is absolutely catastrophic for the cars elecronics.
A new alternator is expensive of coarse, but you can always find a secondhand one. The problem is that you can not check the alternator for functioning, before installing on the car, so there is a risk, but in my country it would cost around 50 Euro.

 

[Karabiner98k]

Please look at this picture:

The one on the left is my original voltage regulator and the one on the right is the faulty one but it seems to have healthy brushes.

Can I remove those healthy brushes and install them on my old voltage regulator and fit it on my car?

 

[CrunchSlaughtered]

You need a soldering iron with a flat tip, because of the limited access. You keep it pushed to the place where the brush is held and after it is heated enough the brush will pop up. I doubt that you can use the brushes from the other regulator, because to mount them you need a longer wire of the brush and after you solder it you just cut the excess. The used brushes are already with cut wire so it's length won't be enough to put it through the hole and solder it.

 

[Giannis]

I have been told not to change the brushes because they say by doing this, it will work for a few days and stops working again.

Nonsense. I remember changing the bushes of my Clio's alternator around the 250.000 km mark and they were fine at around 350.000 km when the two copper strips on the alternator's rotor disintegrated.

I have also been told that high voltage damages electronic devices, sensors and engine ECU. How much does it cost to replace all of them?

That is correct. The cost of replacing all electronics is prohibitive, unless you have the time and patience to locate each faulty item and source a cheap used part.

The new set of brushes will last about 200 000 km, if they are original. If they are not original and are harder they will wear fast the copper bush of the alternator and it is much harder to be changed, if they are softer they will wear for 30 000- 50 000 km. Otherwise the high voltage is absolutely catastrophic for the cars elecronics.
A new alternator is expensive of coarse, but you can always find a secondhand one. The problem is that you can not check the alternator for functioning, before installing on the car, so there is a risk, but in my country it would cost around 50 Euro.

Exactly. I believe you can find original bushes on e-bay? This isn't something I've tried fixing myself yet.

You need a soldering iron with a flat tip, because of the limited access. You keep it pushed to the place where the brush is held and after it is heated enough the brush will pop up. I doubt that you can use the brushes from the other regulator, because to mount them you need a longer wire of the brush and after you solder it you just cut the excess. The used brushes are already with cut wire so it's length won't be enough to put it through the hole and solder it.

And you are quite correct again.

 

[Karabiner98k]

So, to sum it up:

I should replace my brushes and the ECU and the electronic devices and the wiring.

 

[CrunchSlaughtered]

So, to sum it up:

I should replace my brushes and the ECU and the electronic devices and the wiring.

No, only the brushes. The rest if it is working is still ok.

 

[Karabiner98k]

No, only the brushes. The rest if it is working is still ok.

Ok, but you said high voltage is absolutely catastrophic for the cars electronics. So, according to what you said my electronics have been ruined too.

 

[mini_cooper4]

Change the brushes first as others have suggested.
Stop driving or even starting the engine of your car until you do so.
Once you change the brushes see if anything is acting up.
At last have someone read your codes and see what shows up just to make sure all is good.

 

[Karabiner98k]

I have a PSA code reader (Actia). I can read the codes if there is any.

 

[Giannis]

That would be a good idea!

 

[mini_cooper4]

I have a PSA code reader (Actia). I can read the codes if there is any.

Great! Even more money and hassle saved.
There's a high chance you'll be perfectly fine after just changing the brushes but I'd still read the codes for the peace of mind. Even if there's a problem pinpointing it pre-disassembly saves time and money.

 

[Karabiner98k]

Thanks for giving me hope!
I hope I won't have to replace the entire engine for a faulty voltage regulator.

 

[Karabiner98k]

Today, I disconnected the alternator and took my car for a spin with the battery alone. To my surprise, everything was fine and there was no fast idle. The engine performance was perfect!

Tonight, I worked hard for 3 hours to be able to remove that hateful voltage regulator that caused problems.
I managed to remove it with the alternator in its place but I had to open the oil filter to get access to the back side of the alternator. It was really hard! I removed the air intake, throttle body, intake manifold and fuel rail!
Now I want to discard the faulty voltage regulator and use my car's original regulator but with new brushes and see what happens.

 

[Giannis]

Good luck mate!

 

[Karabiner98k]

I removed the faulty voltage regulator and found someone who changed the brushes of my original voltage regulator.

This is my original voltage regulator:

The new brushes installed on it:

I fitted my voltage regulator with new brushes on the car and put everything back into place (Intake manifold, throttle body, fuel rail, etc)

I was ready to start the car with new brushes!

I started the engine but the battery seemed to be weak and didn't have enough juice to turn the starter motor but the engine started up. The battery warning light was still on and I checked the battery voltage with the engine running and it was 9.1 Volts! So, the alternator wouldn't charge the battery!

I turned off the engine and decided to jump start it. I used my father's car for this purpose.
I jump started my car and let it idle for 2 minutes (With my father's car engine off). The voltage was increased from 9.1V to about 12V but reduced gradually to about 11.89V. Then I revved the engine a bit and let off the throttle. About 1 minute later, voltage increased to 14.3V! The alternator started working and was charging the battery! The battery warning light disappeared!

I took the car for a spin to see what will happen. Everything was fine and the engine behavior was perfectly normal. After about 30 minutes of driving, I pulled over to check the voltage and it was still 14.3V! I revved the engine to make sure the voltage regulator is working properly and the voltage didn't go higher than 14.3V regardless of RPM! It prevented over-charging! It seemed the voltage regulator was doing its job!

I came back home and hooked up my PSA ACTIA code reader to check if there were any faults and there were no faults found:

What do you think now?
Why the alternator didn't work during the first two or three minutes?
Do you think the problem was solved?

I turned off and on the engine several times to make sure the alternator is working and the voltage was 14.3V, no problem.