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Tachometer reading incorrect

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Old 07-28-2013, 09:17 AM
  #1  
Vet76te
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Default Tachometer reading incorrect

My 1975, (L82 / 4spd manual), tach seems to be reading incorrect. At idle, it "seems" to be reading correct. Reads right around 1000rpm,...and the engine sounds to be about that speed.

However, as you drive at higher speeds, the tach seems to be reading much too fast.
  • At 60mph it reads between 4,000 and 4,500 rpms.
  • At 70mph it's reading 5,000 rpms.

The engines does NOT seem to be turning up anywhere near that fast,..so I'm assuming the tach is calibrated wrong.
  • Would this be a printed circuit board issue,...
  • a distributor connection issue,...
  • or a guage issue?
Old 07-28-2013, 10:33 AM
  #2  
0Willcox Corvette
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In this case the board would be the only thing I would try...

As the cars are aging I'm seeing more and more failures in the movements of the tachometers. While the board will probably solve your problem, there is a possibility the movement might be the issue.

I have left dash pad removal instructions on the web site should you decide to remove it.


Corvette Left Hand Dash Pad Removal Made Easy 1968-1977

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Last edited by Willcox Corvette; 07-28-2013 at 10:36 AM.



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