Tach Sensor ?
 

is there a such thing, the reason why im asking is because in my 91 the tach goes rite to redline and i changed out the cluster and it does the same thing, i was told that it is a tach senser i was wondering if this is true.

thanks

The factory tach is wired through the dizzy I think on all HEI cars. Check those connections first.

-Tim

theres a single wire that runs from the dizzy, I believe it is brown. if its small cap it runs from the ignition module

sounds like there might be a wiring problem other than the cluster or dist. after hacking the wiring out of my race car my tach and speedo do the same thing.

The tach runs off the white wire from the coil with the small cap dist.

yea there ptob is a wireing prob, becuz that doest work and the car doest start nomore. it starts then dies, then now it doesnt start at all i cut out prob 120 pounds of wireing that was put in from the org owner, so i think i might to switch dashes out and see what happens.