Battery light blinking (did search)

[GRY_03TDI]

Battery light blinking (did search), it's the pulley!

My 2003 Jetta has about 80k on the clock and it started blinking the battery light in certain circumstances.
1. Starting from a stop at about 1800rpm it will come on for one second then go off (seems to come with the turbo spooling).
2. When the transmission shifts or when the torque converter locks up.
Based on this I think it could be either a bad belt tensioner that can't handle the change in RPM or a bad voltage regulator that is not reacting fast enough to the change in RPM. I ordered both of these from Impex today along with a new belt and want to know if there is anything else I should replace while the alternator is out (what a pain)??
I did take the existing alternator to auto zone and they gave it a clean bill of health. This is the 90Amp bosh alternator PN 038-903-023-L.
Thanks in advance guys.

 

[boraTDI04]

i would say belt tensioner, whats the battery read while the car is running? 13.5-14 V should be the range for a properly working V.R.

 

[GRY_03TDI]

i would say belt tensioner, whats the battery read while the car is running? 13.5-14 V should be the range for a properly working V.R.

The car is down now, but I will report back when it is all buttoned up next week. Since the VR is pretty easy to get to even with it on the car I will try the tensioner first and then pop the VR in.

 

[weasel]

My first thought is that the belt was slippping. Tensioner would be a good thing to check. Or you could just have something slippery on the belt. Belt dressing should help there. As to the voltage while running, my Scangauge reports 14.2 -14.4 volts most of the time.

 

[GRY_03TDI]

It's the pulley

After putting it all back together and starting it back up it makes a horrible sound and the battery light comes on and then it goes off. Acts just like when an A/c clutch locks up.

It wasn't doing that before I took it out, was this just the first sign of pulley failure? My alternator is part number 038-903-023-L (90 AMP) and I can't seem to find that one. Impex has a 024-ax and it is $436 bucks! Can I just get the clutched pulley somewhere or is it best to just r&r the alt. and be done with this?

Also, can I use a 120 AMP alternator since they are half the price of the 90?

Thanks.

 

[weasel]

Hmmm, I would have thought you had the 120 ... I'd take it apart again and verify that everything spins freely and without wobbles ( like a toasted bearing would do ). You should be able to use that 120 amp without issue provided it is a diesel alternator.

 

[GRY_03TDI]

Hmmm, I would have thought you had the 120 ... I'd take it apart again and verify that everything spins freely and without wobbles ( like a toasted bearing would do ). You should be able to use that 120 amp without issue provided it is a diesel alternator.

The pulley has some play in it that I don't think should be there. It does spin freely though. I found the 90A remanufactured Bosch at autohausaz.com PN: F4000-161506 for $225 so I am just going to pop that in when it gets here later this week. I should have just replaced the whole thing because the Voltage Regulator I bought is electrical and therefore, not returnable. Anyone want a VR on the cheap?

Stay tuned as the saga continues....

 

[GRY_03TDI]

All Fixed.

The new alternator solved all the symptoms and the car is running fine now. Glow plugs at 72k alternator at 80k, what's next?? Oh ya, timing belt

 

[weasel]

Rule of three's !! Suspension will be soon, brakes ... fun isn't it ?

 

[GRY_03TDI]

It's great. I did the battery a while back so hopefully that is the trifecta. The ball joints and tie rods still feel great and my brake pad still have over 50% life at 80k miles. Love that highway mileage.