2002 Toyota Corolla Front Windshield Wiper Problem

Hi, the windshield wiper on my car started to slow down, sometimes it would have difficulty making an entire movment, then finally it stopped moving.

I replaced the wiper motor however when I turn on the car and use the wiper switch, the wipers just studder as if something is not allowing the motor to move, even though it would like to.

I know the motor itself works fine 100%, what would be the problem?

thanks.