Is your odometer digital like mine?
Mine is going on and off as I drive. I'm thinking that it has something to do with the gauge cluster harness where it plugs into the back of the cluster.
Going to take it off and plug it back in to see if its just a connection issue.
1999 3.8 stang
1990 LX - supercharged 351w
1985 turbo 2.3 www.msvorinich.itgo.com