Alternator Stopped Working (2001 VW Golf 2.0L)
 

My friend has a 2001 VW Golf 2.0L that stopped charging. Battery voltage was 11.5 volts unloaded, and with the engine running stayed at the same voltage. I figure he could have a bad ground, bad fuse, bad relay, or bad alternator.

I charged him up enough to get the car to a European mechanic, who wants to charge $340 just for the alternator. The mechanic also said it needed to be replaced without doing any diagnostic at all except for what I had already done.

I found a black wire going to the alternator and measured resistance to ground, and found it open. Should the wires circled in the picture below show continuity to ground?

http://i7.photobucket.com/albums/y26...m/KIMG0179.jpg

My friend doesn't have much money, and I don't like the "replace parts until it starts working" philosophy of repair work. If you know what I can check, and where to look, that would be great.

The smaller wire is the field excitation signal from the engine computer. The larger wire goes to the positive terminal of the battery. Neither wire should show a connection to ground.

My question is: Where is the serpentine belt?

Yeah, where's the belt?

Also that little wire looks pulled tight to me... if there is a fault with it, I'd suspect a break in the wire right at the connector where it is pulled into a hard bend.

Oh, and friends don't let friends have newer VWs... AND THE $340 ALTERNATOR IS THE REASON WHY.

Thanks guys. I'll see if I can keep my friend from the poor house...

The belt is on the alternator, it just has the ribs out.

Is the belt flipped? Maybe it has no traction and nothing is spinning properly.

Some serpentines ride pulleys on both sides.

regards
Mech

All the alternators I have ever seen had the serpentine ribs contacting the pulley surface. The above picture is not showing that.

Now I'm confused...

Looking at pictures from a Google search, it appears the belt is ribbed on both sides.

http://www.iloveme.net/otherpics/tensionerbefore.jpg

http://img.photobucket.com/albums/v3...y/DSC09222.jpg

http://upload.generationdub.com/images/DIYserp06.jpg

http://quirk-images.com/ebay01/vw2/06A-260-849-C-x.jpg

EDIT: Posted at about the same time as redpoint did... hadn't ever seen a belt ribbed on both sides before... cool!

Was also trying to find a pic of the routing, and this is what I found:
http://i340.photobucket.com/albums/o...project_88.jpg

No AC on that one though...

From DIY: Serpentine Belt Replacement 2.0 / 1.8T (MKIV)

Update:

My friend found a re-manufactured alternator for $130 and the absurdly expensive European automotive shop charged $100 to put it in. $230 out the door... and I warned him about buying a VW. At least he is saving a ton of money in gas now that he's out of his Ford Exploder.

dang.. I saw this thread too late. Usually all that is bad on the Bosch VW alternators is the brushes. You can buy new brushes for less than $50. take the alternator off, unscrew the plastic cover, unscrew the brush holder, reassemble. Yes, the proper belt is ribbed on both sides.

Thanks Ted. If it were my car, I'd have fixed the alternator after diagnosing it as the problem in the first place. The issue was that my friend needed the car going quickly, and I was in the middle of my 13hr work shifts for the week. No time for me to become an expert on VW charging systems. Impatience costs money.

Hopefully your post helps someone else.

That said, I think I've got a bad brush on a starter motor in a Honda Rancher ATV. I hear the solenoid click, but no cranking and the amp draw stays low... come to think of it, I may have replaced the brushes once already on it.

It seems like you fix one thing, and two other things break in the meantime.