Audi A6 1.9 TDi AFN battery light onarte

[ksareen]

Hello,

Hope everyone is doing well.

My car is 1999 Audi A6 1.9 TDi 110 bhp saloon (Engine code AFN) with 100K on clock but no service history. I've had it since it had 82K on the clock.

The car has recently had a new DMF and a clutch plate, then serviced 500 miles ago.

Started the car today morning, the battery meter is not going beyong half mark. Opened the bonnet and there are some squeaky noises, sometimes from belt and sometimes within the alternator I think.
Tried to shake the alternator and engine sound changed, battery meter moved to 12 but then back again at half after a few seconds. Now shaking the alternator does not help and the battery light is flickering in the cluster.

Does it need a new alternator or is there a loose connection that can be checked? The alternator is right on top near the front of bonnet and sticker on it says that its 14V 120A, part number is 038 903 018 BX 01.

Thanks for your help in advance..

[Peter D]

It does sound as if the alternator has failed. Do you have a meter and can you read the voltage across the battery, it should be 13.75 to 14.25 when the enhige is running but with all options tuned off even the heater fan. Regards Peter

[ksareen]

Hi Peter

Thanks for your reply.

I do have a muiltimeter but would you not trust the voltmeter inside the cluster? Also the battery telltae is blinking ON/OFF.

Is there any wiring check that I need to do before I order a replacement alternator?

The alternator is quite easily accessible. Is there any DIY instructions to do replace alternator or is it best left to a mechanic?

[Peter D]

As I said "It does sound as if the alternator has failed." You asked for advice, I gave it, and then you question it. Just do the test then check the connections at the alternator and battery and remeasure the battery voltage. The meter in car is probably indicating correctly but descriptions like "the battery meter is not going beyond half mark" is not a voltage. The fault could be the brush set or a failed diode pack. You had better be sat down you your get a quote for a new alternator. If you repair the one you have then I suggest you change the Sprag clutch alternator pulley whilst it is off. How many miles has the car done. Regards Peter

[ksareen]

descriptions like "the battery meter is not going beyond half mark" is not a voltage


If you have driven these A6s, you would know that the meter/ gauge has volts as its measurement for display. I also said that battery lamp is blinking.

Anyway, I will take measurements tonight and update.

[Peter D]

I know what you said and as I stated "It does sound as if the alternator has failed." How many miles has the car done. Regards Peter

[ksareen]

Good question

The odometer reads 100K now and I've had the car for 1.5 years since when it was 82K but I don't have any service history on this car :confused:..

Since I was planning to sell it when the DMF failed a month ago, I am now considering buying a second hand alternator from scrappy and do a swap.

[Peter D]

What does the charge light do with raising RPM. At 110 this could just be worn brushes. Regards Peter

[ksareen]

The charge light did not come on in the first start. That was just me noticing that the battery voltage gauge has not moved after cranking the car.


On the second attempt, I opened the bonnet and shook the alternator and wiggled the wires/ connectors. The guage then moved to the right for a few seconds before coming back accompanied by blinking charge light.

Raising the rpm does not make any difference but please allow me to re-check when I get home tonight and update.

Thanks..

[Peter D]

PM me your email address and I'll send you the details for checking the brushes. What make of alternator do you have. Regards Peter

[ksareen]

Hi Peter,

PM is sent, please check.

Thanks..

[NickPicks]

If you have driven these A6s, you would know that the meter/ gauge has volts as its measurement for display. I also said that battery lamp is blinking.


I think Peter might have driven a few of these A6s. ;)

The dashboard relies on a voltage sensor to activate the voltmeter, so if that's faulty, you could be replacing several hundred quids worth of alternator just for the want of sticking a multimeter on the battery terminals to check that it's not just a dodgy sensor or dash panel.

[ksareen]

Hi Peter

Took the readings last night.
Battery= 12.2 V; IGN = ON, engine = not running
Battery=11.8 V; Engine running

Some belt sequel and "kat-kat" noise from alternator was there.

Revving the car to 2K does not make any difference, charge lamp was still flashing.

Took the car to my mechanic (2 miles away). With the windows rolled down, I could hear "kat-kat" noise from alternator and occassional belt noise.

About 100 yards from his garage, the charge lamp disappeared and the voltmeter inside cluster went to over 12V. The "kat-kat" sound disappeared and belt noise became more pronounced.

Explained to my mechanic, he stuck the multimeter on the alternator for about 10-15 minutes, the voltage was steady around 14.05V. Revving made no difference.

He has asked me to come back when the problem arises again but says that I might as well come back with a new alternator should this issue become more persistent as he cannot do anything else.

Have driven the car 30 miles since then, the issue has not resurfaced.

Your thoughts please!!

[NickPicks]

I've had charging problems on previous cars which have turned out to be the alternator brushes worn down. Replacing these usually costs about £10 compared to £200 for a new alternator. It could be that they've worn down and got stuck so the springs aren't pushing them in, and somehow they've unstuck just before reaching the garage.


If you're getting more belt noise now, then that'll need looking at. I think it's often the one way clutch in the alternator pulley (I think Peter called it the Sprag clutch). You can check this by watching the belt while someone turns the steering to full lock - the belt will flap more if the clutch is siezed.

[ksareen]

Hi Nick

I've to admit that a little belt noise was always there. However, it does go away after warming up.

Could you please advise where would I be able to get brushes for my alternator?

Would alternator have to be removed to replace brushes? Is it a DIY job?

Thanks..

[NickPicks]

I don't know about the specifics of this model, but my previous cars have had bosch alternators, and the brush pack just unbolts from the back really easily. I don't know if you have to take the alternator out to get to the back of it though.

I think the last set I got from German and Swedish. They don't list them on their website, but they had them in stock. I'd expect any decent motor factors to be able to supply them.

[Peter D]

Why are you asking about how to do the job, I sent you the drawings for the bosch unit. For the alternator to remover form the problem, and if it was the brushes then one or both of them must ahve been stuck in it's holder. Blow some compressed air though the rear cover to clear out the carbon dust and see how she goes. Regards Peter

[Peter D]

My appologies Nick, I did not read your post #14. Regards Peter

[ksareen]

Nick

This is what I found online:

If your 120 Amp (Bosch) alternator is P/N: 038-903-018-B or BX you need a voltage regulator P/N 038-903-803-E

Are the brushes part of regulator or do I need to buy them seperately?

Peter
I just managed to covert your mdi files into pdf for viewing. Thanks for sending the manual. It seems that in order to replace the brushes/ regulator, the alternator does not need removing, the back plate comes off with 2 nuts + 1 bolt and the brushes/ rectifier can be taken out through there.

Blowing compressed air is a good idea. I'll try that soon.

Thanks once again for your help.

[ksareen]

Hello again

The "charge lamp & alternator not charging" issue has not re-surfaced in the last 300 miles. Still need to visit my mechanic to get compressed air.

The only issue is belt sequel/ whistle at cold idle and low rpm (just at the time of taking off). It goes off eventually but does my head in when windows are down and the car is cold.

I tried the belt test that Nick mentioned:

watching the belt while someone turns the steering to full lock - the belt will flap more if the clutch is siezed

This is not the case, so could it be that the belt is loose?

Also, my friend is scrapping his 2007 VW GOLF 1.9 pd, with 45K miles. Engine code is BXE. Would anyone know if I can use his alternator? I believe the output to be same as mine (120A)

Your advice is much appreciated. Thanks.

[mrp0ny]

My alternator on my 1.9 AFN finally went at 440K.....

Fo a few days the guage was up and down a bit against its normal reading. And then one day I left it for 2 days and it wouldt start again....I thought it was the battery (which had done >300K!).....but a couple of days later it was obvious it was the alternator...

These cars are hewn from granite and the 1.9AFN is the daddy of them all.....definitely worth hanging on to as it will still be going and giving 40+mpg when all the new ones are broken nursing their gearboxes etc...

Mrp0ny

[ksareen]

Hi again
The charging has been OK for the past month and the charge light has not been ON. Not driven the car much as I've been away for holidays for 2 weeks.

But the belt noise is too intrusive if the window is down a bit. I showed it to the mechanic and he says I should replace the one way clutch in the alternator pulley (Sprag clutch). He says that although the clutch is available seperately, I should also replace the alternator at the same time as my charge problem could still come back anytime.

My question is that if I buy an alternator from scrapyard/ fleebay, would the sprag clutch be automatically included? Does anyone have a pic so I can see how it looks before I place the order?

Thanks.

[NickPicks]

If you buy one from a scrapyard or ebay, how do you know it's going to be better than yours?

Personally, I'd be inclined to remove yours, check the length of the carbon brushes and replace them if required, replace the sprag clutch and refit it. I'd then expect it to last for another 100,000 miles.

If the brushes are still quite long, then it sounds like they just got stuck and have now been freed up and are making contact OK.