wiper motor park intermitent

The park switch is on top of the gearbox. You'll notice it can be rotated under the retaining screws so mark it's current position before removing.
Cleaning the contacts,etc.., in there should cure it.
Please note; the motor pictured above is a different animal and has common electrical wires. Yours has single strand leads under asbestos sleeves. Be careful with those. They can become very brittle with heat and age.