The Vehicle Speed Sensor is located on top of the transmission. I believe the two wires at the sensor are Green/orange and the second wire is green. When the VSS fails the speedometer and cruise control fail, as well as the Check Engine Light comes on. If the Speedometer gauge itself has failed the cruise control may still work.
On the speedomoter. This what Mitchell OD5 says the location is. This supposedly is factory infon. Upon closer study. It's on the trans and it's a AC pulse generator. That means when you pull it out of the trans & hook a volt meter in the AC position & spin the gear it should produce at least 1/2 volt AC. AUTOTECHPAT is correct. the colors of the wires are green/orange and green.