Need help diagnosing electrical problem

[DGAFxxx]

The night before last I noticed my battery wasn't holding a charge. Normally the guage shows it holding a steady 15-16v. It was only reading about 12v. After driving the car for a bit it kept draining the battery till the point the car just died. I jumped it and let the battery charge for a good 20 min off the other car.

After driving it home it drained the battery again. Normally with a bad alternator I would think the battery guage my fluctuate with the RPM. It doesnt do that at all. It's almost like the alternator is unplugged. I checked the wires, don't see any loose wires.

Any ideas or any methods for testing other than the cheap autozone tests?

[Ewok_Fetus]

Voltage regulator in the alternator took a shit... That won't cause the gauge to flucuate when revving the motor... Also, 15-16V is a little high... Yes, you need an alternator... What is funny is it seems that every time I have a problem, a whole wave of people have the same problem... And testing it... You can only confirm what your in dash gauge is telling you... Battery is good since it runs for a bit... Alternator is shot...

[whoace]

Get it AVR'd...Starter Draw and Alternator output.

[DGAFxxx]

thanks, anyone know where to find a write up for replacing the alternator?

[DGAFxxx]

Well it's definately the alternator. The alternator was only putting between 10-11 volts out. Just trying to decide if its worth the money to take it in to have a shop replace it. I've been quoted about $350 in labor just to replace it.

[GetAwayFromMe]

The alternator on a 1.8t should take you about an hour to do 30min or less for a good mechanic. Do some search and find a DIY write up borrow some tools if you dont have any and do it yourself. If your car was a 2.8 than $350 would be worth taking it in. I have done a few on a 1.8t and it usualy takes me about 30min. If you were around my area i would help you out for a case beer.

Good luck with it.