# Mk3 Tach not working, cluster is good.



## 20vTa4 (Jun 21, 2001)

The car is OBD2 VR6, The speedo,coolant temp and fuel gauge work, tach does nothing. So far, I've tried 2 other clusters (known to work), another ecu, checked continuity on all the sensor wires back to the ecu, replaced the fuse box, and tried a new cluster harness. 

The ecu is definitely getting an RPM signal, I can see it with vagcom, but somehow it's not getting to the tach. 
This thing is driving me crazy, am I missing something obvious?


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## zwogti (Jan 11, 2004)

well you can run a wire from green/black on the computer box, to RPM signal going in the back of gauges to see if it works that way, this way you can tell if gauge is good or not. Also you can get a after market rpm gauge, get a signal from the green/black from the computer box, see if it will work to make sure you are realy getting the rpm from the computer, if not I will say the tranmission speed sensos is not working or the gears on it inside the tranny is stripped, by rotating very slow some times it could trick the vagcom and read it as it is working or maybe the rpm sig wire is broken inside?


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## wolfyy98 (Aug 28, 2008)

Having this same issue, ive replaced my transmission speed sensor and still does the same


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## 20vTa4 (Jun 21, 2001)

wolfyy98 said:


> Having this same issue, ive replaced my transmission speed sensor and still does the same


VSS has nothing to do with your tach signal. My problem ended up being a short to ground on the tach signal wire.


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