Hi XXXXXXXXXXXXXXXXX.
Thank you for asking your question on Just Answer.
This is likely a problem with the multi-function switch (wiper switch) The wiper switch supplies the circuit for the ground to park the wipers at the motor. Replace the multi-function switch will likely fix your issue.
ASE Certified Technician
23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs