speedometer

The car uses an electric speed sensor that generates voltage as the car gets driven. Does the cruise control work if so the speed sensor works and the speedometer head is the most likely problem. From what I see on a wiring diagram if the fuel gauge tachometer and temperature gauge work then the power supply for the speedometer and speed sensor should be OK. Using an oscilloscope or ac voltmeter the speed sensor can be tested to see if it is producing a signal or not.