Alternator? Battery? Help Please! 98 A4 1.8T
 

So I recently had my engine blow on my car, after 3 long weeks of having to go shop to shop I finally got it back in perfect running order....or so I thought. Turns out I was driving and all a sudden it died on me yet again. I waited about 5 minutes and it started again but was definitely hurting to get it going. Now it won't start, not sure if anyone has had the same problem. I checked the battery and it sits steady at about 11.5V so I think its fine, as for the alternator not sure how to go about troubleshooting it. I hope someone could give me a hand and let me know if you have any solutions. Thanks
Cheers!
Randy

Re: Alternator? Battery? Help Please! 98 A4 1.8T
 

your battery should sit at 12V when engine is off. It should climb up to 13.8 or so when you start the engine. It should stay there with all your acessories running, its normal if it dips a little. If your voltage doesnt rise high enough to 13.5 or above, either your serpentine belt tensioner is loose or your alternator is going bad.

if your battery stays at 12V with engine off, and can stay at 12V while running the radio and blower for a while, should be ok to assume that your battery is good.

Re: Alternator? Battery? Help Please! 98 A4 1.8T
 

Ok awesome sounds like it's my alternator then cause the battery when running is about 12.6 and when the car is off it's at 11.4 so most likely it's the alt. Do you know how to test it at home? Just so I can do it all myself, I'll pick up an alternator and try installing myself.
Thanks for the help!

Re: Alternator? Battery? Help Please! 98 A4 1.8T
 

hi the way I test the alternator is very basic , I turn everything on in the car while running and then disconnect the negative to the battery. If the car still runs then the alternator is suppling more than enough power and it is good. Hope this helps.

Re: Alternator? Battery? Help Please! 98 A4 1.8T
 

^ sounds like a good way to test it too. thanks for your input!