Tach Adjustment - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• Tach Adjustment by Sam Johnson on 17 Jan, 2009 22:17
• All,
  
  Recently I had installed a Mk II diesel tach in my 1988 Vanagon DL that has a 1.9 TD AAZ engine.  It fits perfectly and works just fine but reads too fast (1600 rpm when the engine is around 1000 rpm).  Can someone tell me which direction, clockwise or counterclockwise, I need to adjust the calibration pot on the circuit board to reduce the reading closer to the correct one??
  
  Thanks for any suggestions.
  
  Sam
  Tucson, AZ
• #1 by fatmobile on 17 Jan, 2009 22:38
• It's hard to adjust because you can't get to the adjuster while the cluster is plugged in.
   I desoldered my adjuster and it hangs outside the cluster.
   Easy to adjust.
   Sorry, I have no idea which way I turned it.