Tack stoped working tranny won't shift

[aaronr19]

I have a 93 f250 7.3 and my tack stopped working all together making tranny go in limp mode and I just bought a tack sensor still not working.. When I start truck the tack will bump up to like 100 rpm and go to 0. NEED truck to run right have to take it to work. Could it be a pinched wire or possibly a fuse?

 

[turbo elk]

Mine did that it was the tach sensor.