Passat Cluster GURUs: No Tach, No Speedo, No Fuel Gauge & other minor issues

[G60ING]

I had my car in the garage without a battery for a couple months while doing various work. Well now I have put it back together and fired it up for the first time. The car runs great EXCEPT the tach, speedo and fuel gauge doesn't work. All of the lights work (including the CEL) when the car is turned on but if I unplug the gp relay and EGR valve and then turn on the car the CEL doesn't stay on. The CEL codes will be registered but the light stays off after the initial few seconds. The Vag-com can read the tach and speed. Does anybody have any thoughts on what could cause all these problems? The temp gauge works.

I've checked the wiring and I can't find any issues but it doesn't mean that I could have been blind.

here is the cluster lit up:

 

[bigrichard]

Double, triple and quadruple check the quality of the ground contact for the three wires near the right side of the head. If you didn't mess with the cluster harness or any wiring at the fuse block and nothing looks obvious, i would minimize stress and contact Derek White.

 

[Nash_TDI]

Do passat clusters have a low voltage issue?

 

[G60ING]

I've contacted Derek. I've cleaned the ground wires on the head but I did mess with wiring by the fuse box and hence my issue of being uncertain. I'll wait for Derek to get back to me, he too suggested I check the head's grounds.

Yes B4 Passat clusters are known for their issues, so much that it might cause one to ignore other issues and thats what I'm trying to avoid.

 

[ajrn]

I'm having cluster issues after a head remove/re-install..

The ground wires were removed/cleaned re-installed, but I'm still having issues.

Fuse 21 seems to be okay. The tach/temp/speedo are erratic, and the odometer/clock "shut off"..

Hard to say what other issues await me, but I'd like to keep the car running long enough to set the timing with the vag-com-- not sure if I can (or should) be connecting one, while this is going on.

What grounds on the head are there?? I don't remember removing any to pull the head..

This thread http://forums.tdiclub.com/showthread.php?t=324092 has me wondering if my problem isn't from the huge harness connection near the head-- I've looked a couple times, but don't see any "issues.."

 

[G60ING]

did you disconnect the batter terminals while doing the work? clean these up and the individual wires running to the battery terminals.

 

[G60ING]

Oh and my issue turned out to be that the motors were burned up from pushing on the needles too far...derek took care of me. I confirmed my cluster was the problem by getting an OBD2 VR6 cluster and plugging it in.

 

[ajrn]

both ends of both (body and engine) grounds were removed, cleaned, and re-installed. I actually have a separate ground that runs from the block to the starter. Again, I didn't remember removing any ground wires from the head-- are we talking about the one that goes to the block/bellhousing area??

It's common for an additional wire from the block to the starter motor (usually a 4g solenoid to starter type) with MB diesels, and VW makes it pretty easy, with the starter bolts with nutted ends.

I'm still really thinking I may have disrupted something in the huge connection in front of the head.

 

[RIP TDI]

The cluster secondary ground is the solid brown one of the 3 head grounds. VSS and ECT grounds are the other two.