My tach doesn't work which is really annoying because I like to know what's going on. I can still tell what RPM im at, but I just want to be sure. But it does work sometimes. On the freeway when I go over a small bumb it just comes to life sometimes, or if it's working it will just go out. The instrument pannel was changed a couple of months ago, and that didn't change the problem. Anyone have an idea of what it could be?