For the past month, I have been having charging system problems. While the engine is running, the voltimeter in the dash dances wildly around, usually settling between 12 and 10v. In the past, it has always stayed steadily at 13-14v. Last week, as I was driving home, the engine half-died on me because the system is not providing any charge to the battery. I have replaced the battery (which happened right before the symptoms started), because the car kept dying during the day and I'd have to get a jump every night just to get home from work. The alternator has been replaced twice.
I have a 2000 1.8T (ATW) w/ 120A Valeo alternator. I have swapped out my alternator twice with reman 120A Valeo's. After three alternators, the problem has gotten progressively worse, leading me to conclude that the problem is most likely not the alternator. No one can test the alternator because their testers are not configured for it, and I can't get the car to have the system tested because it won't run. I have one aftermarket electronics item- an amp that is connected but not powered up (nothing is attached to it). Tonight, after putting the third alternator in, I jumped the car. It ran for five minutes and died, with the battery completely discharged. The battery is a die-hard, if that's any help.

I appreciate any insight that anyone can offer me as to how to further troubleshoot. I am going to remove the battery and get it tested hopefully tomorrow. For the sake of argument, let's say that I can rule out the alternator and the battery. I can't see it being a short because the problem is intermittent and varies in impact. Anyone have any suggestions? Thanks.

 

my car is a 2000 ATW, running with die-hard battery from Sears (have had it for about 1 year). Its been running strong this year and today (3/2), the battery just took a dump on me.

Initially I would see just slow voltage drops, but it got to the point that the battery was totally drained (voltage went all the way to 8v), and car just died. My suggest was also on the alternator, but after reading this post, I am having 2nd opinion; possibly on the battery.

Hopefully someone would have an idea to fix this.