Speedo has power (light) but does not work (no speedo or odometer). I followed the black red and white wires from the sensor to the speedo to ensure continuity and all is fine. Also pulled the speed sensor (VSS)and cleaned off the filings that had accumulated on it. Still not working. I'm stuck. is there any way of testing if the sensor is emitting a pulse when the tire is spinning? which of the three wires are supposed to emit the pulse and would I be able to measure this with a volt meter set to DC? Before i go through the trouble and expense of replacing the VSS i would like to confirm that its defective. Any help or advice would be appreciated.