Audi A4-how do i know if my alternator is bad or

"alt is started the lights" WHAT DOES THIS MEAN?
THE ALTERNATOR LAMP GLOWS OR WHAT.
TELL ALL TH AT WORKS GOOD AND BAD. OR DEAD
car starts and drives,????????????

Rad fan stuck on even a dead cold engine?
Rad fans as the sticker under hood says can come on automatically.
at any time,even key off, (the engine is too hot)
tell all good and bad, cars are complex tell the full story.

taking the battery leads of a running alternator is one sure way of destroying the alternator
if you think a battery is dead you have it load tested and replaced if it doesn't meet the test
what you should be doing is taking the vehicle to an accredited auto electrician and having the battery load tested and the alternator and voltage regulator professionally tested for proper operation

get your car fix right now
2002 Audi A4 Workshop Repair Service Manual PDF Download

you mentioned new alternator and battery, but it seem that the alternator is not charging, when you install the new battery the car started and run and after hours of running specially if head light is on the car shuts down. this is an indication that the alternator is not charging. (factory defect) have it checked or return part to auto supply.
if alternator is good and you have the car jumped and run it will not shut down even if your battery is dead because the charge of the alternator is enough to power the electrical system of the car until you turn it off. this applies to all cars

usually strange electrical problems like this turn out to be related through a bad ground somewhere - hope that helps a little - the battery in the fob will not cause these issues - good luck and have a nice day :O)

once you get it started,while its running,simply disconnect the positive battery wire. if the car stays running then your altenator is fine,and its the battery thats bad. if it dies immediately,then the altenator is shot and battery is fine.

sounds like the alternator is not charging the battery, when it doesnt start are you sure the battery is dead, i know you jump it but a faulty starter can od that also, if there are no inside lights or radio or headlights dont come on then its the battery and its defective or the alternator is not charging all the time may be bad,good luck hope this is helpful.

Voltage regulator is going bad. Have alternator tested or go ahead and have it replaced. Also this would be a good time to have the battery tested. Usually an alternator that is over charging will "cook" the battery causing it to not charge, not hold a charge, to losing the gel/electrolyte solution due to boil out.

Take it to an Audi dealer. Could have been a bad alternator, and another bad alternator if they didn't use Audi part. Don't use cheap rebuilt Chinease stuff on your Audi.

You will need to put the car on a scanner to reset.