'02 Jetta alternator light blinking

[quartersaw]

My Jetta ALT. warning light blinks on and off briefly at speed, but seems OK @ idle. When I start the car up, I get that 'bad belt tensioner ' 'chirp' that I used to hear in my B4V.
It's cold,and snowy here, so I am going to see if I can get away with replacing the voltage regulator assembly, instead of replacing the alternator. The car has 282k miles, so I'm thinking that it might be warn brushes in the alternator.
- Think that I am tempting fate, or are the two situations with the blink & chirp unrelated?

 

[jayb79]

one way clutch on the alternator is slipping, don't wait too long to change it failure sometimes can be messy.

 

[Tdijarhead]

Mine’s chirping a bit also, alternator pulley clutch not the regulator. I’ll do mine when I do my timing belt next month.

 

[csstevej]

Yep......gonna be the clutch........
Just did this on my daughters NB a few months back.

 

[quartersaw]

So, I should simply replace the alternator, or is this pulley clutch a separate thing?

 

[Genesis]

The clutch can be removed IN THE CAR most of the time (unless it's REALLY badly stuck) if you have the proper tools for it. This is most-likely the cause and yeah, it's a "fix it now" sort of thing in that sometimes when they fail entirely they come apart instead of locking in the "on" position and the parts flying around can cause all sorts of bad outcomes.

Push comes to shove you can remove the alternator and then take the clutch pulley off on the bench. I bat about 50/50 on being able to get it off in the vehicle -- sometimes you just can't get enough leverage to get it off without pulling the alternator first and jacking the inside bit into a vise.

 

[BobnOH]

So, I should simply replace the alternator, or is this pulley clutch a separate thing?

Further diagnosis needed. Rule out the clutch pulley, the tensioner, big wires and connects, battery.

 

[Genesis]

What Bob said. Odds, giving the noise, however (and the fact that the other things being driven by the belt are ok, including power steering, etc) point to the pulley.

 

[jokila]

I had an alternator flicker the alt light on the dash. Turned out it was the bearings on the nose of the alternator. It affected my mpg slightly.

 

[BobnOH]

Good point. Could definitely be a bad alternator. It might be prudent to rule out the other "dumb stuff".

 

[quartersaw]

It was quite cold here today, and the car started w/o the 'chirp', and the blinking ALT light didn't happen until I drove the car about 45 miles. The light started blinking as I pulled into my driveway @ home. :-(

 

[quartersaw]

Sorry for the late reply, but I replaced the Alternator, and all is well!

 

[JB05]

Thankyou for the update; better late than never.

 

[jayb79]

Did you put on a new pulley with the replacement also?

 

[quartersaw]

Did you put on a new pulley with the replacement also?

I cheaped out, and bought a junkyard alternator. I pulled the brush/diode assembly out, and replaced it with a new one.
One of the ears was cracked on the alternator in the car, so it had to go.

 

[BobnOH]

Check that your tensioner is not bouncing around, it may have been damaged with the alternator fail.
Otherwise, Nice Work and thanks for posting back!

 

[jokila]

I cheaped out, and bought a junkyard alternator. I pulled the brush/diode assembly out, and replaced it with a new one.
One of the ears was cracked on the alternator in the car, so it had to go.

Cracked ears happens when people hammer on the threaded sleeve to get it back into position to reinstall. The best way to get the sleeve back into place is to use a socket and C-clamp to squeeze it back into position.

 

[quartersaw]

Check that your tensioner is not bouncing around, it may have been damaged with the alternator fail.
Otherwise, Nice Work and thanks for posting back!

I did replace the tensioner. The bearing,was toast!

 

[quartersaw]

Cracked ears happens when people hammer on the threaded sleeve to get it back into position to reinstall. The best way to get the sleeve back into place is to use a socket and C-clamp to squeeze it back into position.

It was a real mess, in there. I had assumed that it was the original installation, but at 275k, maybe I was being a bit presumptuous.