I drive a 1998 Ford Ranger 3.0L and after I drive it for about 20-30 minutes the speedometer will drop to zero. A couple of times I hit the dash hard enough and it started workin again. Would this be the cluster going out or the speed sensor itself? Let me know. Thank you

 

The speed sensor is shared by the abs system, so no abs codes it should be fine.

My tach has a case of not wanting to work, I know there is a bit of corrosion on the cluster contacts. As I have cleaned it off before.