Alternator Stopped Working (2001 VW Golf 2.0L)

[redpoint5]

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?



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.

[t vago]

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?

[Frank Lee]

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.

[redpoint5]

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.

[Frank Lee]

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

[user removed]

Some serpentines ride pulleys on both sides.

regards
Mech

[t vago]

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

[redpoint5]

Now I'm confused...

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

[NachtRitter]

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:


No AC on that one though...

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

[redpoint5]

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.