While properly grounding motor apply proper voltage to the low- speed terminal at motor, if the motor does not run replace it. If the motor runs check the motor switch, controller and wiring
Motor will not run on high speed
While properly grounding motor apply proper voltage to the high-speed terminal at motor, if the motor does not run replace it. If the motor runs check the motor switch, controller and wiring
Both motors in a two motor system will not run on either low or high speed or both
It is unlikely that both motors low or high speeds circuits would fail at the same time so check the controller switch and wiring
Motor runs but arm(s) and blade(s) are stationary
Check the drive arm on the end of the motor output shaft to see if it’s slipping.
Check the attachment at the wiper arm to see if it’s slipping on the shaft. Some arms have a conical shaped knurled driver under the wiper arm that can crack or strip and lose the attachment
Arm(s) and blade(s) wipe properly but do not park in the correct location
Check the drive arm on the end of the motor output shaft. It may have slipped and needs to be indexed and tightened to the proper torque.
The arm may need to be remounted correctly on the shaft (pivot shaft)
Arm(s) and blade(s) sweep properly but don’t park and stop at random at any location on the window
If the system has two motors and both arms and blades don’t park check the switch and controller. If one arm and blade does not park check the park circuit on that motor (in some cases testing the motor park circuit can’t be done in the field)