I just bought a green mica 97 A4 1.8 turbo as my family saloon, I didnt want to give in to the Honda craze like so many of my friends have done Anyway, I wired up my starter yesterday and it works with a toggle switch for now until I can get a replacement ignition switch. Last night, my A4 would start up great, but die shortly after because it had no voltage at the battery. So I charged the battery overnight, put it in, it started right up, didnt die out. So I took it for a drive, and noticed the voltage slowly dropping from 12V down to 10V over the course of maybe 10-15mins of driving. What is wrong with my A4?

 

alternator - not charging the battery as the car drives.

 

Ditto , alternator not charging.

 

Thanks guys I will take in the alternator to have it professionally rebuilt and report back.

 

lol what?
just buy a brand new one?

 

I cant find new ones. Everywhere I look that actually ships to Hawaii offers only remanufactured ones...

Also, I had my alternator tested and its good... So on a hunch I disconnected my negative battery cable and put it to the side. Took my multimeter out and ran the red positive testing lead to the negative battery pole and the black negative tester lead to the negative battery cable and my meter read -12.2DCV... Hm...not sure on that one. A short somewhere?

 

You charge your battery and without turning the car on, let it sit. Is the battery dead after a few hours? That would mean something is draining it but while driving of the car is losing power it's still the alternator.

 

Loose serpentine tensioner

 

Dont forget to check the belt. Get a Bosch reman they are good & reliable.

 

More Info: 1997 Audi A4 1.8t FWD Auto

After letting it sit for an hour, the battery did loose voltage. I disconnected the alternator wiring and checked my multimeter - still at -12V. I pulled every fuse in the driver side dash compartment, no change other than voltage returning slightly when I pulled the 20A fuse for the stereo(aftermarket Kenwood Excelon), pulled every relay under the steering wheel, and checked the large blade fuses and silver ones - still was at -12V.

I'll still get the alternator replaced though.

Belt is tight. I cant move it.

Where do you get your Audi parts from?