Ok, guys and gals. My 90 vette apparently has a tach that is unique to the 90 model year, though I'm not sure why. My problem is that when my engine idles, the tach reads 4500 rpm, as soon as I give gas, the tach tops out, and eventually, shuts down. It's been doing this since I bought the car 2 yrs ago. I have had the cluster out twice, gone through it with elctronics cleaner(corrosion etc.). All the other gauges now work like a charm, axcept for the tach. I tried replacing and removing the silver can hooked up at the distributor, doesnt change a thing. Someone once told me that there is a power supply under the dash, that went bad. Any help would be great! Thanks!

 

if youve got msd ignition you might need an msd tach adapter