Chosen Solution
The 1996 Audi A6 Quattro cars battery gauge will jump up under acceleration but doesn’t seem to hold charge even after long periods at high R P Ms dies at idle I had it tested at AutoZone they stated must be Alternator but the Voltage regulator much cheaper part and a fix I could manage, the alternator not so much . Any information as how to diagnose one from the other would be greatfully welcome.
You can test you alternator with a voltage meter . With the motor off get a reading it should be around12.6v then with the motor running it should be 14.2v but if its over 14.6v you have a issue with regulator. If you’ve burned out 2 batteries in a week your looking at the voltage regulator but most regulators are inside the alternator. If moneys an issue try an auto wreckers . Cheap place for parts and your dealing with an old car so why not put an old part on . Probably last as long as the car and if it doesn’t you can get 3 or 4 alt at a wreckers for the price of a new one. One of them is bound to outlast the car. https://www.youtube.com/watch?v=LGB6ZEjG… this is a good video to show you proper test
Keith, this should explain how to check Alternator vs. Regulator.
