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Model Specific Questions and Info => MK3 Golf/Jetta and B3/B4 Passat => Topic started by: XPNinja on September 27, 2015, 10:43:15 am

Title: MK3 AAZ Cluster problem
Post by: XPNinja on September 27, 2015, 10:43:15 am
Hi. I have an AAZ Golf 3. I bought a new cluster because of the rpm tacho, they said its for AAZ. It works, but not really  ;D . I have taken a video of it.

youtube.com/watch?v=F_cHRnCHISE&feature=youtu.be
Title: Re: MK3 AAZ Cluster problem
Post by: vanbcguy on September 29, 2015, 12:42:06 am
Can you describe the problem? On my phone the YouTube link doesn't work and my effort level is poor at the moment...
Title: Re: MK3 AAZ Cluster problem
Post by: libbydiesel on September 29, 2015, 01:31:46 am
The tach doesn't move until he revs it up a bit and then it jumps up and starts working. 

Does it work properly after it is 'jump started'?  I have not owned a stock AAZ, but based on other VW diesels I've owned I would have to say that is fairly normal.  The tach runs off the alternator W-signal.  The alternator needs to be 'excited' before it starts charging and until it starts charging, the tach will not work as the alt is not yet generating a W-signal.  Some VW alts excite more easily than others.  You might lessen the issue with a new regulator/brushes, new alt, or refreshed wiring/connections on the 'blue' wire and ground, but it's also fairly likely that you'll still have to blip the accelerator to 'jump start' the alt/tach.
Title: Re: MK3 AAZ Cluster problem
Post by: vanbcguy on September 29, 2015, 12:00:51 pm
Gotcha.

The blue excite wire to the alternator probably isn't connected or the dash light has failed. The two AAZ vehicles I've owned both excite the alternator fine without revving, I've had those symptoms though when the excite wire wasn't connected. Both the exciter wire and the W tach signal wire share a 2 pin connector on the alternator, check for damaged wires around there to start.
Title: Re: MK3 AAZ Cluster problem
Post by: libbydiesel on September 29, 2015, 12:07:22 pm
It's very common that the red battery light will not go out prior to a little blip on the accelerator.  Regarding tach operation before the light goes out, I've seen both.  Sometimes the tach will work before the alt is excited and sometimes it won't.  On the tachs that worked before the charging light went out, I assumed that it was residual magnetism in the alt that was enough to generate the tach W-signal, but not enough to generate more than battery voltage and so the dash light stayed lit.  While that explanation has credibility, as you say, it could also be an issue with alt or wiring. 
Title: Re: MK3 AAZ Cluster problem
Post by: Spokerider on January 20, 2017, 10:32:55 am
Old post, I know, but thot I'd keep the "cluster" questions here.............

 I have a 1995 Golf and the oem speedo / tach is not working. From googling this problem it looks to be pretty common with Mk3 vw's. I suspect the problem is inside the cluster itself, and not a ground problem, as I think the needle vibrates for a little while when the ignition key is in the "on" position.......supposedly a tell-tale sign of a problem inside the cluster. Also, the odometer works well and counts kms, as do the coolant and fuel gauges.

 Has anyone figured out and posted exactly what goes wrong inside the cluster? Is it something that I can fix?
 
Thanks for chiming in.
Title: Re: MK3 AAZ Cluster problem
Post by: vanbcguy on January 20, 2017, 05:01:33 pm
There are some posts on VW vortex covering exactly what fails, my understanding is it is often one of the gauge stepper motors going bad which causes the controller to get confused. I believe there is a DIY repair available providing you can source another cluster for parts. There are also a few providers out there who can repair your cluster for a fee.

If the mileage displayed isn't all that important I have an AAZ Jetta I'm stripping, the cluster is working 100%.

Sent from my XT1097 using Tapatalk

Title: Re: MK3 AAZ Cluster problem
Post by: Spokerider on January 21, 2017, 11:55:13 am
Thats what I've been researching too. I think a good used cluster is the way to go.

I'll send you a PM about your luster vanbcguy.
 Thanks for the reply.
Title: MK3 AAZ Cluster problem
Post by: Timothycrock on January 31, 2019, 01:03:34 pm
Fixed the problem.

Bought a new pump and it needed ATF Red fluid, who wouldve known?