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General Information => Troubleshooting => Topic started by: okron1k on March 23, 2006, 09:48:42 am

Title: Tach problem.
Post by: okron1k on March 23, 2006, 09:48:42 am

i have this problem with the car since i got it in january. sometimes, but not all the time.. the tach needle will just do whatever it wants.. usually just drop down to zero and back up. i'm guessing it's a loose connection somewhere.. but where do i look? or what else could it be? any ideas?

Title: Tach problem.
Post by: bhtooefr on March 24, 2006, 03:41:05 pm

Check the connection that plugs into the "W" terminal on the alternator.

Title: Tach problem.
Post by: ccices on March 28, 2006, 05:43:31 am

same problem here.
Tach sometimes works, sometimes is dead.
Problem is, nothing I have shows me where to trace the tach connections to. Anyone have a diagram of where it is wired up?
91 Jetta 1.6l TD

Title: Tach problem.
Post by: snootworks on April 27, 2006, 06:01:59 pm

I was kinda hoping someone else might have had this problem!

The tach in my '86 Jetta has always been a little funky...  After startup, the battery light will be on and the tach would either not move, or just sit at ~1000rpm (even with slight fluctuation via the throttle.)  Blip the throttle, battery light goes off and the tach works.

The battery light part I get, and the corresponding tach action too.  I replaced the alternator (thrashed bearing) and the light/tach stayed the same.

Now all of a sudden it doesn't work at all.  There's constant 12v at the W terminal now - and I've never thought to check if there was before (when the tach worked.)