I have a 1992 F-250, 460ci and the tach reads "0" with key on before starting. Immediately upon starting the Tach reads 2500 and stays there
never moves.
Any ideas would be greatly appreciated.
Roger

 

Either it's faulty or not wired correctly. Is it factory or aftermarket?

 

It's factory. Never been touched to my knowledge. When you say faulty, you mean the gauge or the distributor or the wiring possibly?

Thanks for your input.
Roger

 

Well if the distributor was messed up I doubt it would run
It could be the gauge itself has failed or maybe wiring
My tach is aftermarket so I'm not sure how the factory is wired but mine is wired to the negative of the coil
It obviously has power since it moves. But it's not getting signal

 

DO YOU HAVE ANY IDEA AS TO WHAT THE VOLTAGE SHOULD BE? iT PROBABLY IS THE GAGE ITSELF. kNOW HOW TO CHECK IT?

THANKS
ROGER

 

Other than changing the gauge out. I'm not sure how you could test it. I'm hoping someone else may make input on this