Hey all. Thanks for taking the time to check out my post.

2001 A6 2.8 Quattro 118,000 miles

Just yesterday my battery warning light went on when I turned on the air conditioner. I went to Autozone and recharged battery to 100%, it was down to 45%. After re-installing battery, they ran a diagnostic thru the battery terminals. Battery, and starter came back fine but voltage regulator came back as a fail. I've researched around the board and I'm under the impression that the voltage regulator can be changed on existing alternator.

My question is, would their diagnosis of bad volt reg also possibly mean bad alternator or are they able to distinguish from the two? I'd certainly like to get away with the least cost but am just unsure of how far that diagnostic tool will work into the problem.

Any help would be appreciated. Thanks again.

 

There are 3 things that can go bad in an alternator. 1 voltage regulator, 2 failed bearing, 3 internal short.

Now, 99% chance your voltage regulator is at fault.

 

I got the same issue, put a new regulator and didnt fix it. You need a new alternator bro

 

Thx guys. I'll let u know which it turned out to be.