hindswillrox

Ok I have done more testing, The battery is not the issue as I am reading 12 volts from the battery and 9.6 volts with the cranking test. With the engine running from idle and when reving the engine I am reading around 11.5 volts. I would think I should read 1 or 2 volts more not less if the alternator was working properley. On another note I had a valve cover leak and replaced the gaskets about two weeks ago, I cleaned as much of the oil off of the alternator as I could although there may be some oil in the alternator. I think I should note I used the Audipages wright up on the valve cover gasket job, This wright up calls for a torque setting of 18 LBS. I perchased replacement bolts from the dealer and found them to break at around 15 LBS + or -.

silverd2

You should be getting a reading of at least 13.5 volts at idle...the alternator isn't putting out at all or you've lost connection between it and the battery.

Bolts breaking at only 15 ft/lbs ?? A paperclip shouldn't break that easily. Stripping or breaking? I would be very suspicious of the torque wrench's calibration, if breaking. If stripping, maybe the same OR previous bolts were grossly over-torqued(?)

tozoM8

Check the power junction behind the front passenger's side wheel. Corroded connection causes the same symptoms.
http://audipages.com/tozo/positive%20cable.JPG

hindswillrox

I would like to start with the fact the I have had a great deal of Mechanical experience my problem is I just had four screws put in my foot due to broken bones and am unable to do S###, So my 21 year old son is helping with this issue. He has done a lot of work on his Porsche 944 including an engine swap. He happened to be back from school this weekend and drove the Audi and noticed the battery light, asked me if he could use the forum to help his mom as this is her car, He has helped me maintain this car for years. So here is what he is telling me. He let the car run for 10 to 15 minutes with all the accessories on and it completley drained the battery and stoped running. I don't believe a corroded cable would drain the Battery that is fully charged this quickly. I would put the car in the air and look at the cable if I could walk. My son will come back next weekend and do whatever work that needs to be done. I am going to order an alternator $200.00 at Pelican parts, I would assume I could purchase the 150 Amp alternator over the 120 Amp but the A8 have a more complicated electrical system that most cars I have owned and the word assume could = $$$$.$$ if we get it wrong. In the mean time my wife will drive my Porsche 996, she does not like to drive it, It has no cup holder - morning coffee.

Thanks for the Help,

tozoM8

That cable junction connects the alternator to the battery. It will not charge if it is corroded.