I don't know about the '00 Windstar, but my '96 uses a mechanical speedometer, and therefor does not use the VSS to display the speed. The VSS is only used by the PCM & Cruise Control. Transmission shifting is (obviously) determined based on VSS input. When my VSS malfunctioned (bad connection), the O/D light on the steering column flashed, and it stored a code to that effect.