I did it on my first ffr but i cannot locate the drawing. Also has low speed and high speed toggle.

92 95 Wiper Motor Self Parking Switch Operational Questions
Wiper motor park switch. This switch mounts on the wiper motor. Slide the whole connector blockpark switch assembly in the direction of the arrow to remove it from the motor casing. Inside the wiper motor is a park switch. Wiper motor park switch continued replacement delco switch for use on models with depressed park or hidden windshield wiper arms. When using this switch with the universal stainless wiper motor 911 23502 the switch will be wired from the s terminal on the motor to the l terminal on the switch. Off position will park the wipers.
The h and p terminals will remain unused for this application. A short tutorial on how to wire up a windshield wiper motor including the park feature. Standard motor products ds414 standard motor windshield wiper switches compare switch windshield wiper labeled plastic black chevy gmc each. Once you turn the wiper motor off the motor still needs voltage to return the wipers back to the park position. I have been searching with no success. We use a lot of these in our halloween scares for our walk through haunted house.
A separate wire provides that voltage until it reaches the park position and then the switch breaks the connection. I am looking for the wiper electrical drawings that use a manual switch and relay assembly to run the wiper motor including the self park feature. I do not want to use the lucas switch as it does. However many suppliers show a picture of the clip on type under the screw on type part number so you need to be careful when buying a replacement. A ground wire will then be wired from the b terminal on the switch to a grounded location.