I dont have a Windstar but i have a Saturn SL1 but its the exact same problem, my rpm's work but my speedometer dont and when i hae my lights on at night my odometer is lite up, and my radio i cant read(which it could be the radio itself) is it electrical or what?

Dear friend-if the speedometer is not and it is a dail type then remove the cable from the speed sensor.let somebody look at the dail take the cable in your hand and the inner piece between your fingers,spin that inner between your fingers oneway and if it is not working spin it in the other direction,if it wotks then the speed sensor is at fault,if not it could be the dail itself,the illumination lights on the radio is dead.