Crazy Tach?

[dereklee]

Alright, well, here is todays latest question, sorry about all the questions hahah, HOPEFULLY at some point I get everything sorted out!

So this just started very recently, my tach started sitting at 0 rpm, while the motor was obviously not at 0 rpm, and then while driving, it'd bounce up and down, sit at 0, work perfect for a min, bounce, die..

Any suggestions? Which wire is it that connects to the tach at the dizzy?