Installing a Tach

Okay i've got a 1999 Sonoma with a Cavalier engine swap. I've tried to install a Tach into the truck and my problem is the Tach is very crazy. i can be driving it and it will act like it reves and then goes back down to like 1500 rpm. Its a 2.2 5 speed. Any help is appreicated!

FIXED it! yay!:grinyes: i read a post on another forum and it was a Whiteish/Tan colored wire that hooked up to the guage cluster on the grey side!:runaround:



heres the link
http://www.s10forum.com/forum/f105/easy-tachometer-installation-50487/



:rolleyes: