In 1998 Rangers there are 2 relays in the engine fuse box for wipers
These Relays are controlled by the GEM(generic electronic module)
When you turn on the wipers with multi-function switch that signal goes to the GEM
The GEM then activates the Run/Park Relay to send power to the High/Low Relay which sends power to the Wiper Motor.
You can test the relays with ohm meter and 9v battery
But there is no over all test that I know of for the GEM, if you have/get a Ford Service manual it will have circuit tests for GEM connectors, but there is no plug and play test for them
I have a 98 Ranger, The wiper goes straight into LO, no intermittent, then regardless of how it is turned on, it will not park. Any best ideas? I am thinking that it may be the wiper motor never hitting the park switch inside it. But it could easily be the GEM.
Can anyone tell me where is the GEM located?