Before starting to test the wiper motor circuit, make sure that your battery is fully charged and in a good condition. In case the wipers are still moving slowly, you should check the linkage and pivots for binging or damage. Repair or lubricate as necessary. See if there are any loose or corroded connections in particular the ground connection. If all connections look fine then change the motor out. If the wipers don't work, check the 
Fuse and reestablish grounding if necessary. If it doesn't work yet try this: Remove the motor from its mounting bracket and check it outside of the vehicle for voltage in HI position. It cannot be repaired; replace it with a new one in case after checking these parts it does not work properly because of binding linkage. Replace the motor if this doesn't resolve it either. There isn't any voltage available, so diagnose wiper control relays and have switch tested by someone else. Test for continuity between switch and wiper control module for intermittent function problems since there might be something wrong with them too. To inspect "park" problem with wipe, see whether voltage exists at park feed wire or not with open motor to fuse panel circuit; otherwise try changing windshield wiper motor as follows: Take off protective cap together with retaining nuts for wiper arms; mark where each arm was placed and take them out; separate cowl cover from electrical connector; unscrew mounting bolts of linkage/motor assembly; remove both components from mountings leaving only grease on moving parts for which first one needs to be ready to install in place of removal because rear window wiper has similar procedure except: Remove protective cover as well as nut on stub arm (showing correct position) before lifting up those parts carefully following removing their protective cover containing nut spacer coupled rubber seal used over shaft followed by putting back trim panel while having disengaged connector alongside taking away screws that hold down tailgate trim panel and removing motor out of there (installation should be done in reverse order).