I have a 2003 Impala and the wiper blades are not working correctly. On mist they go up once and go down normally but when they go up the second time and come down they stop for a second the proceed to park position. When I put them on level one they go up and down the first time correctly but the second time they just get stuck on the down stroke, but when I switch it to park they go to park. I am a apprentice technician and was just looking for some insight. I believe it to be the transmission for the wiper arms. What do you guys think?