# tachometer suddenly stopped working



## woolsey10 (Oct 18, 2011)

my tach and other gauges have always worked just fine but i was driving the other day and it was working one minute and the next it wasn't and it hasn't worked since. my other gauges are still working. does anyone know why this is or know how i can diagnose and or fix this problem? my car is a 66 lemans with a pontiac 400 and turbo 400 transmission. thanks in advance.


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## BearGFR (Aug 25, 2008)

The two most likely causes are a dead tach, or the signaling wire from the igntion coil / HEI lead is disconnected.

Bear


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## ppurfield001 (Jan 21, 2008)

BearGFR said:


> The two most likely causes are a dead tach, or the signaling wire from the igntion coil / HEI lead is disconnected.
> 
> Bear




:agree -- Just fixed a loose wire that knocked out my hood tach last week. Remember, if your tach is a hood tach, there is significant vibration due to the location of the tach. Good luck.


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## geeteeohguy (Feb 2, 2008)

I've had a bunch of GTO's with the factory tach, and the only one I've ever had that actually _worked_ is the one in the '65 I have now and have owned since '82. In fact, can't believe it still works, as the dead tachs I had in previous GTO's were only 12-15 years old at the time...not 47!! Common for these units to wear out/go out, they were not really super high end to begin with, are old technology, and were not meant to last 50 years. My recommendation is to remove it and send it to Peter Serio for an overhaul/checkout. The guy is THE guy to go to for Pontiac dash and shifter related stuff. He's on the performance years forum.


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## woolsey10 (Oct 18, 2011)

thanks everyone i'll look into that. by the way it is not a hood tach it is on my steering column and is a sunpro super tach II.


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