my rpm gauge doesnt work..anyone have any ideas what could be wrong?

most likly you face sticker has slid down and it binding the needle.

I read a post Ray made a couple days ago explaining how to fix it, if you can find it.

Pretty much take the tach out of the guage cluster, take off the face and reglue it back where it's supposed to sit. Be careful removing the needle and make sure to put it back right where it was when you took it off.

It seems to be a common problem.