We have classified the 3 complaints from 1999 Ford Ranger about VISIBILITY into the following categories.
While traveling with the windshield wipers on, the wipers pause without indication. this occurs in snowy or cold conditions, the wiper motor freezes. dealer suggested to pour hot water down around motor to fix. *ak *ml
The wipers will turn on without turning on switch, and will turn off when switch is set to "on" just like theford explorer problem you are currently investigating