Flashing battery light and burning smell

[s4BoostKing]

So after I drove home from my 40 mike commute to work. I noticed my battery light was intermittently flashing. It was not a constant flashing pattern. I also smelled a burning rubber smell. From what I read so far everyone says the alternator is going out. But no one mentions the burning smell. I looked at the belt with the car running and it seems fine and isn’t slipping. But that was my first guess that the belt was slipping and cause the burning smell and the flashing battery light. I turned the car off and started it again which it started right up but the light continued to randomly flash. What do you guys think?

[S4_NE]

Check grounds on the car, if they are bad it could explain the warning lamp in and out as the voltage may be all over the place. when my alternator crapped the bed it just stopped charging no smell. You can wile it is running check with a DMM to see if you are getting 13-14 volts on the battery terminals after you start up, GL

[s4BoostKing]

So I started the car this morning and after 2 minutes of warming up there was a good amount of smoke pouring out of the hood.. still got the flashing battery light.. strong smell of burning rubber. But the belt is fine and not slipping and all the pulleys are spinning. Can’t pinpoint exactly where the smoke is coming from other then the front end. I might finally be giving up on this car after 10 years of blood sweat and tears with it. I just can’t trust it anymore

[christianb5s4]

I would disconnect the battery immediately if I were you, there's clearly an electrical short in the wiring that's causing that smoke. If it's creating that much smoke it's more than capable of burning your car to the ground.

[blitz2190]

what ^ he said, also for it to throw smoke like that and not short a fuse I would look at the battery to starter/alternator wire shorting out its the only thing I can think of in that area that would not cause a fuse to blow.

[CELison]

Check the starter wire that runs down the pass side frame. It’s under a plastic covering. My friends car lit on fire Bc of a short there.

[s4BoostKing]

Dang. I’m at work now. I’m pretty paranoid I’m gonna go home to a car on fire. At least it’s supposed to downpour all day in my area

[s4BoostKing]

About a month or so ago I kept having fuse #29 blow constantly. One day it went away never really found out what it was.. maybe this is related????

[S4_NE]

Holy crap, I would stop driving it and pull the battey terminals off ASAP, the fuse blow may have something to due with it, off top of my head i dont recall what #29 is , GL

[s4BoostKing]

It’s one of the ECM fuses I believe

[s4BoostKing]

Battery is 12v when off and 14v when running.. used vag com and zero codes.. the smoke is coming from the front passenger side I’m gonna check the wiring to the starter and alternator

[s4BoostKing]

Wiring all checked out and good.. but I found some wet black tar/gunk inside the alternator if I can figure out how to post pics on here I’ll do that tomorrow. Also the alternator was extremely hot after only running the car for 2 mins I burnt my finger. You guys think it’s the alternator putting out the smoke? I’m afraid to run my car anymore in case it is burning wires somewhere else

[bmwpower603]

If there is black stuff on your alternator. This means that the bearing inside the alternator that drives the pulley is probably roasted. And what’s happening is, the belt is slipping on your alternator pulley, because the pulley no longer wants to spin. The friction between the belt, and the alternator, are causing it to smoke. With this, rubber is melting onto your alternator. This is also causing a battery light to flash on and off, because the alternator pulley isn’t spinning adequately enough to produce charge.

Time for a new alternator. And voltage regulator. And whatever else you can change while your in there.

[s4BoostKing]

It’s weird because it looks like the pulley is spinning fine on the alternator. I’ll post picks here soon

[s4BoostKing]

[s4BoostKing]

Any input? I’ve never seen that stuff inside an alternator. But I don’t want to just go ahead and replace the alternator if there could be a Short elsewhere that cause this

[CELison]

Replace It.

[s4BoostKing]

Replace It.

So you think this is just an issue with the alternator itself?

[bmwpower603]

From looking at the pictures. It seems that the alternator is WHEYSTED.

Replace it.

[cal3thousand]

Those windings are charred and definitely your problem.

That black is likely plastic that has melted inside and is causing the smoke.



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[s4BoostKing]

Sounds good I will be yanking it out tonight

[bmwpower603]

Post more pics of your able to. Once you get the front clip off.

I wonder if the voltage regulator was affected.

[blitz2190]

As they said replace it, it looks like the enamel on the windings has melted and charred which mean the alternator has an internal short or got way to hot

[TwoSnelz]

Please post pics of this so I can plan my alternator change when appropriate!

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[s4BoostKing]

I got the car in service position last night but I misplaced my whole set of Allen sockets.. does anyone know off the top of there head what size Allen socket I will need for the two bolts on the alternator and the pulley???

[s4BoostKing]

After a few days of fighting with the garage to get my “lifetime warranty” alternator swapped out. They completely refuse and “lost” my paperwork. I’m selling this car as soon as I get it running so I want to spend as little as possible on this replacement alternator. I saw a few recommendations for the duralast alternators at autozone. A few of them show up in the searches but none say they fit the B5 S4. Does anyone have the autozone part number that I’m looking for??

[JustManson]

So when you go onto the AutoZone website and login they have this My Vehicle section where you put n your vehicles info and the parts that fit will come up in your searches.

Duralast 12056 is what came up for me (2000 Audi S4)

Their site is pretty spot on with fitment.


Why sell the car? Your the S4 Boost King after all.... ;)




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[s4BoostKing]

Yeah I ended up getting that alternator with that part. Thanks though! And I’m kinda done fixing this car every 3 months. Also I’m at 215k miles and still on the stock clutch and turbos, so I’m gonna end up spending almost twice what the cars worth to get nice turbos and clutch along with the other upgrades it would need. Looking to get a c7 s6 or a b8.5 s4 as of right now

[s4BoostKing]

Another question I had to yank the coolant hose off in front of the alternator to get it out. If I just run the car with the heat on and keep adding coolant will that get all the air out of the system or will I have to bleed it???

[slowSfaux]

Our cooling systems are designed to self bleed over a couple of heat up/cool down cycles. Not even necessary to run the heat as there's always coolant flowing through the heater core. Just fill it, start it with the cap off, and top it off. Put the cap on and go for a short drive. After a warm up and cool down, top it up again.

[s4BoostKing]

Thanks for the help. I finally got a replacement alternator and am taking off work tomorrow to finish this job. I just hate working on it for 30-45mins every night I just want to get it done

[s4BoostKing]

Got everything back together car runs great no smoke, smell, or noises from the alternator. Only thing that worry’s me is when I have the key in the ignition and turned but the car not on, the battery light very slowly blinks. But it starts right up every time and seems ok?? Tested the battery and the alternator with a DMM and are fine. Also the power steering pump is now howling. This is why I wanna finally get rid of the car.

[CELison]

Are you low on fluid or did you disconnect a ps line? If you did, jack the front end up and turn the wheel lock to lock with the engine running.

[s4BoostKing]

I was a little low on fluid so I topped it off. But it was still making noise hopefully it goes away tomorrow. But what worries me more is the slow blinking battery light when the car is off but the key is turned to the on position. Doesn’t blink when the car is running though. Any ideas on that?

[s4BoostKing]

So the power steering issues went away. Isn’t he morning my battery light was still slowly flashing when the car was off. But after my 40 min drive to work it stopped so hopefully it stays away

[B501S4]

Was the battery fully charged once the new alternator was installed? Should hook it to a charger/tender to ensure full charge. Weak batteries or ones deep cycled can shorten the life of the alternator


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[s4BoostKing]

I did not fully charge the battery. I didn’t really think of that. But the battery is only 4 months old and should still be solid. It started right up after I got everything together. That could have been the issue. And after my drive to work it fully charged the battery and that’s why it wasn’t flashing after I turned the car off..

[s4BoostKing]

Still have the flashing battery when the car is off after it hasn’t been driven in a couple hours. Still starts up fine though. I wonder if I damaged the battery somehow when I hooked everything back up

[SoundEfx]

Still have the flashing battery when the car is off after it hasn’t been driven in a couple hours. Still starts up fine though. I wonder if I damaged the battery somehow when I hooked everything back up

This might be it.

[s4BoostKing]

Just had the battery tested and it is fine.. not sure what to do but that battery light makes me nervous