I just put a 89 si cluster in my car wired everything up and the speedometer does not work. could i have pulled on the speedo plug to hard which cause a loose conntection? could there be something wrong with the cluster. and yes they are both made by SN.
make sure the speedo cable is snapped into the back of the cluster and the trans. if it is you can test in by taking it out of the trans side and spin it with a drill. if it works your cable is good. if not its snapped some where.