Wiper motor

Since I have my entire dash torn apart. I wanted to look inside the dash at my seals for the Wiper system. good to go. all replaced.

My problem. ............I know here we go again. I have a 69 fish with a 2 speed wiper motor. They do not park when the switch is turned off. They stop where they are. Here are pictures of the motor mounted to the dash. The lower left mounting stud has a metal clip. Should a ground wire go there??? The two speeds work great. What gauge wire should I use for a ground???

wiper motor 2.jpg

wiper motor 1.jpg