I've got a 2006 Audi A4 2.0t with 58k miles on it. The battery light came on 4 days ago and I took it to the dealership and got the battery replaced and a back brake light fixed. Light went out and today I got in the car and as I was driving, the battery light came on again. This time however, I noticed that the engine started squeaking as the light came on (due to the open window). I noticed throughout the day that sometimes when I turn the car on, the squeaking starts right away and the battery light turns on. Sometimes, it'll be a minute before the light turns on with the accompanying squeaking. It seems as if the squeaking gets worse with engine speed but it wasn't easy for me to determine how accurate that impression was. Any ideas whats wrong?

 

Did the dealer confirm the alternator was working before they replaced the battery? That could be your issue.

 

is the squeal from the loose serpentine belt? maybe it's so loose it's not spinning the alternator. is it difficult to turn the steering wheel while you're at a stop? the power steering pump is in that belt loop too.

 

Definately a bad ALT or loose belt.

 

That's what I had in mind but didn't mention anything when I called the dealership. I haven't had a chance to take it in yet but talked to the service department on the phone. They think it may be a crankshaft valve and had no idea why the battery light was on. Didn't think there is an issue with driving it. They never said anything about the alternator, just that they did a test after replacing the battery and found a little bit of extra draw on the battery but that was it. Is there any way I could try identifying where the squeak is coming from in the engine compartment? The steering wheel hasn't been noticeably harder to turn.

 

Turned out to be the alternator pulley locking up. You guys know where I can get more info on that?

 

Did they say what is causing the pulley to lock up? I would guess that the alternator is faulty (which is causing the pulley to lock up). Although pulleys can be replaced I would think the whole alternator needs to be replaced.

 

They are blowing smoke up your ***.... Some unexperienced tech forget to check the Alt before selling the battery.

The battery light has nothing to do with the battery

The battery light has a wire called an exciter wire that comes directly from the alternator. It only comes on when there is a problem with the charging system